Physical Review: Iron-based superconductors http://publish.aps.org/ Iron-based superconductors articles published in Physical Review Journals hourly 1 2012-02-09T20:06:16-05:00 rss@aps.org assocpub@aps.org 2012-02-09T20:06:16-05:00 en Copyright © 2012 the American Physical Society. Personal use only, all commercial or other reuse prohibited Copyright © 2012 the American Physical Society assocpub@aps.org Phase transitions in spin-orbital models with spin-space anisotropies for iron pnictides: Monte Carlo simulations http://link.aps.org/doi/10.1103/PhysRevB.85.054411 Author(s): Ryan Applegate, Rajiv R. P. Singh, Cheng-Chien Chen, and Thomas P. Devereaux<br/><p>The common phase diagrams of superconducting iron pnictides show interesting material specificities in the structural and magnetic phase transitions. In some cases the two transitions are separate and second order, while in others they appear to happen concomitantly as a single first-order transitio...</p><br/>[Phys. Rev. B 85, 054411] Published Thu Feb 09, 2012 Author(s): Ryan Applegate, Rajiv R. P. Singh, Cheng-Chien Chen, and Thomas P. Devereaux

The common phase diagrams of superconducting iron pnictides show interesting material specificities in the structural and magnetic phase transitions. In some cases the two transitions are separate and second order, while in others they appear to happen concomitantly as a single first-order transitio...

[Phys. Rev. B 85, 054411] Published Thu Feb 09, 2012

]]> Phase transitions in spin-orbital models with spin-space anisotropies for iron pnictides: Monte Carlo simulations Ryan Applegate, Rajiv R. P. Singh, Cheng-Chien Chen, and Thomas P. Devereaux 2012-02-09T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.054411 Phys. Rev. B 85, 054411 (2012) article Physical Review B 85 5 2012-02-09T10:00:00-05:00 10.1103/PhysRevB.85.054411 http://link.aps.org/doi/10.1103/PhysRevB.85.054411 054411 Magnetism Magnetism Magnetic-field tuned anisotropy in superconducting Rb_{x}Fe_{2−y}Se_{2} http://link.aps.org/doi/10.1103/PhysRevB.85.064509 Author(s): S. Bosma, R. Puzniak, A. Krzton-Maziopa, M. Bendele, E. Pomjakushina, K. Conder, H. Keller, and S. Weyeneth<br/><p>The anisotropic superconducting properties of a Rb<span><sub><span style="font-style: italic;">x</span></sub></span>Fe<span><sub>2−<span style="font-style: italic;">y</span></sub></span>Se<span><sub>2</sub></span> single crystal with <span><span style="font-style: italic;">T</span><sub>c</sub>≃32</span> K were investigated by means of superconducting quantum interference device (SQUID) and torque magnetometry, probing the effective magnetic penetration depth <span><span style="font-style: italic;">λ</span><sub>eff</sub></span> and the magnetic penetration depth anisotropy <span><span style="font-style: italic;">γ</span><sub><span style="font-style: italic;">λ</span></sub></span>. I...</p><br/>[Phys. Rev. B 85, 064509] Published Thu Feb 09, 2012 Author(s): S. Bosma, R. Puzniak, A. Krzton-Maziopa, M. Bendele, E. Pomjakushina, K. Conder, H. Keller, and S. Weyeneth

The anisotropic superconducting properties of a RbxFe2−ySe2 single crystal with Tc≃32 K were investigated by means of superconducting quantum interference device (SQUID) and torque magnetometry, probing the effective magnetic penetration depth λeff and the magnetic penetration depth anisotropy γλ. I...

[Phys. Rev. B 85, 064509] Published Thu Feb 09, 2012

]]> Magnetic-field tuned anisotropy in superconducting Rb_{x}Fe_{2−y}Se_{2} S. Bosma, R. Puzniak, A. Krzton-Maziopa, M. Bendele, E. Pomjakushina, K. Conder, H. Keller, and S. Weyeneth 2012-02-09T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.064509 Phys. Rev. B 85, 064509 (2012) article Physical Review B 85 6 2012-02-09T10:00:00-05:00 10.1103/PhysRevB.85.064509 http://link.aps.org/doi/10.1103/PhysRevB.85.064509 064509 Superfluidity and superconductivity Superfluidity and superconductivity Structure of the oxygen-annealed chalcogenide superconductor Fe_{1.08}Te_{0.55}Se_{0.45}O_{x} http://link.aps.org/doi/10.1103/PhysRevB.85.064504 Author(s): Hefei Hu, Jian-Min Zuo, Mao Zheng, James N. Eckstein, Wan Kyu Park, Laura H. Greene, Jinsheng Wen, Zhijun Xu, Zhiwei Lin, Qiang Li, and Genda Gu<br/><p>The as-grown single crystal Fe<span><sub>1.08</sub></span>Te<span><sub>0.55</sub></span>Se<span><sub>0.45</sub></span> with the tetragonal PbO-type structure is nonsuperconducting owing to the excess Fe. Superconductivity is induced after oxygen annealing with an onset and zero resistance transition temperature around 14.5 K and 11.5 K, respectively. The oxygen doping i...</p><br/>[Phys. Rev. B 85, 064504] Published Mon Feb 06, 2012 Author(s): Hefei Hu, Jian-Min Zuo, Mao Zheng, James N. Eckstein, Wan Kyu Park, Laura H. Greene, Jinsheng Wen, Zhijun Xu, Zhiwei Lin, Qiang Li, and Genda Gu

The as-grown single crystal Fe1.08Te0.55Se0.45 with the tetragonal PbO-type structure is nonsuperconducting owing to the excess Fe. Superconductivity is induced after oxygen annealing with an onset and zero resistance transition temperature around 14.5 K and 11.5 K, respectively. The oxygen doping i...

[Phys. Rev. B 85, 064504] Published Mon Feb 06, 2012

]]> Structure of the oxygen-annealed chalcogenide superconductor Fe_{1.08}Te_{0.55}Se_{0.45}O_{x} Hefei Hu, Jian-Min Zuo, Mao Zheng, James N. Eckstein, Wan Kyu Park, Laura H. Greene, Jinsheng Wen, Zhijun Xu, Zhiwei Lin, Qiang Li, and Genda Gu 2012-02-06T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.064504 Phys. Rev. B 85, 064504 (2012) article Physical Review B 85 6 2012-02-06T10:00:00-05:00 10.1103/PhysRevB.85.064504 http://link.aps.org/doi/10.1103/PhysRevB.85.064504 064504 Superfluidity and superconductivity Superfluidity and superconductivity Superconductivity and structural variation of the electron-correlated layer systems Sr(Pd_{1−x}T_{x})_{2}Ge_{2} (T = Co, Ni, Rh; 0⩽x⩽1) http://link.aps.org/doi/10.1103/PhysRevB.85.024538 Author(s): J. W. Wang, I. A. Chen, T. L. Hung, Y. B. You, H. C. Ku, Y. Y. Hsu, J. C. Ho, and Y. Y. Chen<br/><p>Superconductivity variations deduced from the x-ray diffraction and the magnetic and heat-capacity measurements in the pseudoternary Sr(Pd<span><sub>1−<span style="font-style: italic;">x</span></sub><span style="font-style: italic;">T</span><sub><span style="font-style: italic;">x</span></sub></span>)<span><sub>2</sub></span>Ge<span><sub>2</sub></span> layer system [Pd(<span>4<span style="font-style: italic;">d</span><sup>8</sup></span>), <span><span style="font-style: italic;">T</span></span> <span>=</span> Co(<span>3<span style="font-style: italic;">d</span><sup>7</sup></span>), Ni(<span>3<span style="font-style: italic;">d</span><sup>8</sup></span>), or Rh(<span>4<span style="font-style: italic;">d</span><sup>7</sup></span>); <span>0⩽<span style="font-style: italic;">x</span>⩽1</span>] are reported. For the BaFe<span><sub>2</sub></span>As<span><sub>2</sub></span>-type tetragonal structure, the degenerate <span><span style="font-style: italic;">n</span><span style="font-style: italic;">d</span><sup>7</sup></span> or <span><span style="font-style: italic;">n</span><span style="font-style: italic;">d</span><sup>8</sup></span> orb...</p><br/>[Phys. Rev. B 85, 024538] Published Tue Jan 31, 2012 Author(s): J. W. Wang, I. A. Chen, T. L. Hung, Y. B. You, H. C. Ku, Y. Y. Hsu, J. C. Ho, and Y. Y. Chen

Superconductivity variations deduced from the x-ray diffraction and the magnetic and heat-capacity measurements in the pseudoternary Sr(Pd1−xTx)2Ge2 layer system [Pd(4d8), T = Co(3d7), Ni(3d8), or Rh(4d7); 0⩽x⩽1] are reported. For the BaFe2As2-type tetragonal structure, the degenerate nd7 or nd8 orb...

[Phys. Rev. B 85, 024538] Published Tue Jan 31, 2012

]]> Superconductivity and structural variation of the electron-correlated layer systems Sr(Pd_{1−x}T_{x})_{2}Ge_{2} (T = Co, Ni, Rh; 0⩽x⩽1) J. W. Wang, I. A. Chen, T. L. Hung, Y. B. You, H. C. Ku, Y. Y. Hsu, J. C. Ho, and Y. Y. Chen 2012-01-31T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024538 Phys. Rev. B 85, 024538 (2012) article Physical Review B 85 2 2012-01-31T10:00:00-05:00 10.1103/PhysRevB.85.024538 http://link.aps.org/doi/10.1103/PhysRevB.85.024538 024538 Superfluidity and superconductivity Superfluidity and superconductivity Vortex images on Ba_{1−x}K_{x}Fe_{2}As_{2} observed directly by magnetic force microscopy http://link.aps.org/doi/10.1103/PhysRevB.85.014524 Author(s): Huan Yang, Bing Shen, Zhenyu Wang, Lei Shan, Cong Ren, and Hai-Hu Wen<br/><p>The vortex states on optimally doped Ba<span><sub>0.6</sub></span>K<span><sub>0.4</sub></span>Fe<span><sub>2</sub></span>As<span><sub>2</sub></span> and underdoped Ba<span><sub>0.77</sub></span>K<span><sub>0.23</sub></span>Fe<span><sub>2</sub></span>As<span><sub>2</sub></span> single crystals are imaged by magnetic force microscopy at various magnetic fields below 100<span> </span>Oe. Local triangular vortex clusters are observed in optimally doped samples. The vortices are more ordered than those in...</p><br/><img src="http://publish.aps.org/images/icons/prbsugg30x30.jpg" alt="PRB Editors' Suggestion"/> <br/>[Phys. Rev. B 85, 014524] Published Mon Jan 30, 2012 Author(s): Huan Yang, Bing Shen, Zhenyu Wang, Lei Shan, Cong Ren, and Hai-Hu Wen

PRB Editors' Suggestion The vortex states on optimally doped Ba0.6K0.4Fe2As2 and underdoped Ba0.77K0.23Fe2As2 single crystals are imaged by magnetic force microscopy at various magnetic fields below 100 Oe. Local triangular vortex clusters are observed in optimally doped samples. The vortices are more ordered than those in...

[Phys. Rev. B 85, 014524] Published Mon Jan 30, 2012

]]> Vortex images on Ba_{1−x}K_{x}Fe_{2}As_{2} observed directly by magnetic force microscopy Huan Yang, Bing Shen, Zhenyu Wang, Lei Shan, Cong Ren, and Hai-Hu Wen 2012-01-30T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.014524 Phys. Rev. B 85, 014524 (2012) article Physical Review B 85 1 2012-01-30T10:00:00-05:00 10.1103/PhysRevB.85.014524 http://link.aps.org/doi/10.1103/PhysRevB.85.014524 014524 Superfluidity and superconductivity Superfluidity and superconductivity Evolution of transport properties of BaFe_{2−x}Ru_{x}As_{2} in a wide range of isovalent Ru substitution http://link.aps.org/doi/10.1103/PhysRevB.85.024536 Author(s): M. J. Eom, S. W. Na, C. Hoch, R. K. Kremer, and J. S. Kim<br/><p>The effects of isovalent Ru substitution at the Fe sites of BaFe<span><sub>2−<span style="font-style: italic;">x</span></sub></span>Ru<span><sub><span style="font-style: italic;">x</span></sub></span>As<span><sub>2</sub></span> are investigated by measuring resistivity (<span><span style="font-style: italic;">ρ</span></span>) and Hall coefficient (<span><span style="font-style: italic;">R</span><sub><span style="font-style: italic;">H</span></sub></span>) on high-quality single crystals in a wide range of doping (0 <span>≤</span> <span><span style="font-style: italic;">x</span></span> <span>≤</span> 1.4). Ru substitution weakens the antiferromagnetic (AFM) order, inducing superconducti...</p><br/>[Phys. Rev. B 85, 024536] Published Mon Jan 30, 2012 Author(s): M. J. Eom, S. W. Na, C. Hoch, R. K. Kremer, and J. S. Kim

The effects of isovalent Ru substitution at the Fe sites of BaFe2−xRuxAs2 are investigated by measuring resistivity (ρ) and Hall coefficient (RH) on high-quality single crystals in a wide range of doping (0 ≤ x ≤ 1.4). Ru substitution weakens the antiferromagnetic (AFM) order, inducing superconducti...

[Phys. Rev. B 85, 024536] Published Mon Jan 30, 2012

]]> Evolution of transport properties of BaFe_{2−x}Ru_{x}As_{2} in a wide range of isovalent Ru substitution M. J. Eom, S. W. Na, C. Hoch, R. K. Kremer, and J. S. Kim 2012-01-30T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024536 Phys. Rev. B 85, 024536 (2012) article Physical Review B 85 2 2012-01-30T10:00:00-05:00 10.1103/PhysRevB.85.024536 http://link.aps.org/doi/10.1103/PhysRevB.85.024536 024536 Superfluidity and superconductivity Superfluidity and superconductivity Influence of random point defects introduced by proton irradiation on critical current density and vortex dynamics of Ba(Fe_{0.925}Co_{0.075})_{2}As_{2} single crystals http://link.aps.org/doi/10.1103/PhysRevB.85.014522 Author(s): N. Haberkorn, B. Maiorov, I. O. Usov, M. Weigand, W. Hirata, S. Miyasaka, S. Tajima, N. Chikumoto, K. Tanabe, and Leonardo Civale<br/><p>In this work we analyze the influence of random point defects introduced by 3 MeV proton irradiation on the critical current density (<span><span style="font-style: italic;">J</span><sub><span style="font-style: italic;">c</span></sub></span>) and vortex dynamics of a Ba(Fe<span><sub>0.925</sub></span>Co<span><sub>0.075</sub></span>)<span><sub>2</sub></span>As<span><sub>2</sub></span> single crystal. The results show that at low temperatures (<span><span style="font-style: italic;">T</span></span>) the irradiation produces an enhancement of <span><span style="font-style: italic;">J</span><sub><span style="font-style: italic;">c</span></sub></span> of up ...</p><br/>[Phys. Rev. B 85, 014522] Published Fri Jan 27, 2012 Author(s): N. Haberkorn, B. Maiorov, I. O. Usov, M. Weigand, W. Hirata, S. Miyasaka, S. Tajima, N. Chikumoto, K. Tanabe, and Leonardo Civale

In this work we analyze the influence of random point defects introduced by 3 MeV proton irradiation on the critical current density (Jc) and vortex dynamics of a Ba(Fe0.925Co0.075)2As2 single crystal. The results show that at low temperatures (T) the irradiation produces an enhancement of Jc of up ...

[Phys. Rev. B 85, 014522] Published Fri Jan 27, 2012

]]> Influence of random point defects introduced by proton irradiation on critical current density and vortex dynamics of Ba(Fe_{0.925}Co_{0.075})_{2}As_{2} single crystals N. Haberkorn, B. Maiorov, I. O. Usov, M. Weigand, W. Hirata, S. Miyasaka, S. Tajima, N. Chikumoto, K. Tanabe, and Leonardo Civale 2012-01-27T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.014522 Phys. Rev. B 85, 014522 (2012) article Physical Review B 85 1 2012-01-27T10:00:00-05:00 10.1103/PhysRevB.85.014522 http://link.aps.org/doi/10.1103/PhysRevB.85.014522 014522 Superfluidity and superconductivity Superfluidity and superconductivity General mechanism for orbital selective phase transitions http://link.aps.org/doi/10.1103/PhysRevB.85.035123 Author(s): Yu-Zhong Zhang, Hunpyo Lee, Hai-Qing Lin, Chang-Qin Wu, Harald O. Jeschke, and Roser Valentí<br/><p>Based on the analysis of a two-orbital Hubbard model within a mean-field approach, we propose a mechanism for an orbital selective phase transition (OSPT) where coexistence of localized and itinerant electrons can be realized. We show that this OSPT exists both at and near half-filling even in the a...</p><br/>[Phys. Rev. B 85, 035123] Published Thu Jan 26, 2012 Author(s): Yu-Zhong Zhang, Hunpyo Lee, Hai-Qing Lin, Chang-Qin Wu, Harald O. Jeschke, and Roser Valentí

Based on the analysis of a two-orbital Hubbard model within a mean-field approach, we propose a mechanism for an orbital selective phase transition (OSPT) where coexistence of localized and itinerant electrons can be realized. We show that this OSPT exists both at and near half-filling even in the a...

[Phys. Rev. B 85, 035123] Published Thu Jan 26, 2012

]]> General mechanism for orbital selective phase transitions Yu-Zhong Zhang, Hunpyo Lee, Hai-Qing Lin, Chang-Qin Wu, Harald O. Jeschke, and Roser Valentí 2012-01-26T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.035123 Phys. Rev. B 85, 035123 (2012) article Physical Review B 85 3 2012-01-26T10:00:00-05:00 10.1103/PhysRevB.85.035123 http://link.aps.org/doi/10.1103/PhysRevB.85.035123 035123 Electronic structure and strongly correlated systems Electronic structure and strongly correlated systems Nodal versus Nodeless Behaviors of the Order Parameters of LiFeP and LiFeAs Superconductors from Magnetic Penetration-Depth Measurements http://link.aps.org/doi/10.1103/PhysRevLett.108.047003 Author(s): K. Hashimoto, S. Kasahara, R. Katsumata, Y. Mizukami, M. Yamashita, H. Ikeda, T. Terashima, A. Carrington, Y. Matsuda, and T. Shibauchi<br/><p>High-precision measurements of magnetic penetration depth <span><span style="font-style: italic;">λ</span></span> in clean single crystals of LiFeAs and LiFeP superconductors reveal contrasting behaviors. In LiFeAs the low-temperature <span><span style="font-style: italic;">λ</span>(<span style="font-style: italic;">T</span>)</span> shows a flat dependence indicative of a fully gapped state, which is consistent with previous studies. In contrast...</p><br/>[Phys. Rev. Lett. 108, 047003] Published Thu Jan 26, 2012 Author(s): K. Hashimoto, S. Kasahara, R. Katsumata, Y. Mizukami, M. Yamashita, H. Ikeda, T. Terashima, A. Carrington, Y. Matsuda, and T. Shibauchi

High-precision measurements of magnetic penetration depth λ in clean single crystals of LiFeAs and LiFeP superconductors reveal contrasting behaviors. In LiFeAs the low-temperature λ(T) shows a flat dependence indicative of a fully gapped state, which is consistent with previous studies. In contrast...

[Phys. Rev. Lett. 108, 047003] Published Thu Jan 26, 2012

]]> Nodal versus Nodeless Behaviors of the Order Parameters of LiFeP and LiFeAs Superconductors from Magnetic Penetration-Depth Measurements K. Hashimoto, S. Kasahara, R. Katsumata, Y. Mizukami, M. Yamashita, H. Ikeda, T. Terashima, A. Carrington, Y. Matsuda, and T. Shibauchi 2012-01-26T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevLett.108.047003 Phys. Rev. Lett. 108, 047003 (2012) article Physical Review Letters 108 4 2012-01-26T10:00:00-05:00 10.1103/PhysRevLett.108.047003 http://link.aps.org/doi/10.1103/PhysRevLett.108.047003 047003 Condensed Matter: Electronic Properties, etc. Condensed Matter: Electronic Properties, etc. Antiferromagnetic Spin Fluctuations above the Dome-Shaped and Full-Gap Superconducting States of LaFeAsO_{1-x}F_{x} Revealed by ^{75}As-Nuclear Quadrupole Resonance http://link.aps.org/doi/10.1103/PhysRevLett.108.047001 Author(s): T. Oka, Z. Li, S. Kawasaki, G. F. Chen, N. L. Wang, and Guo-qing Zheng<br/><p>We report a systematic study by <span><sup>75</sup>As</span> nuclear-quadrupole resonance in <span>LaFeAsO<sub>1-x</sub>F<sub>x</sub></span>. The antiferromagnetic spin fluctuation found above the magnetic ordering temperature <span><span style="font-style: italic;">T</span><sub><span style="font-style: italic;">N</span></sub>=58  K</span> for <span><span style="font-style: italic;">x</span>=0.03</span> persists in the regime <span>0.04≤<span style="font-style: italic;">x</span>≤0.08</span>, where superconductivity sets in. A dome-shaped <span><span style="font-style: italic;">x</span></span> dependence of the supercond...</p><br/>[Phys. Rev. Lett. 108, 047001] Published Thu Jan 26, 2012 Author(s): T. Oka, Z. Li, S. Kawasaki, G. F. Chen, N. L. Wang, and Guo-qing Zheng

We report a systematic study by 75As nuclear-quadrupole resonance in LaFeAsO1-xFx. The antiferromagnetic spin fluctuation found above the magnetic ordering temperature TN=58  K for x=0.03 persists in the regime 0.04≤x≤0.08, where superconductivity sets in. A dome-shaped x dependence of the supercond...

[Phys. Rev. Lett. 108, 047001] Published Thu Jan 26, 2012

]]> Antiferromagnetic Spin Fluctuations above the Dome-Shaped and Full-Gap Superconducting States of LaFeAsO_{1-x}F_{x} Revealed by ^{75}As-Nuclear Quadrupole Resonance T. Oka, Z. Li, S. Kawasaki, G. F. Chen, N. L. Wang, and Guo-qing Zheng 2012-01-26T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevLett.108.047001 Phys. Rev. Lett. 108, 047001 (2012) article Physical Review Letters 108 4 2012-01-26T10:00:00-05:00 10.1103/PhysRevLett.108.047001 http://link.aps.org/doi/10.1103/PhysRevLett.108.047001 047001 Condensed Matter: Electronic Properties, etc. Condensed Matter: Electronic Properties, etc. de Haas–van Alphen Study of the Fermi Surfaces of Superconducting LiFeP and LiFeAs http://link.aps.org/doi/10.1103/PhysRevLett.108.047002 Author(s): C. Putzke, A. I. Coldea, I. Guillamón, D. Vignolles, A. McCollam, D. LeBoeuf, M. D. Watson, I. I. Mazin, S. Kasahara, T. Terashima, T. Shibauchi, Y. Matsuda, and A. Carrington<br/><p>We report a de Haas–van Alphen oscillation study of the 111 iron pnictide superconductors LiFeAs with <span><span style="font-style: italic;">T</span><sub><span style="font-style: italic;">c</span></sub>≈18  K</span> and LiFeP with <span><span style="font-style: italic;">T</span><sub><span style="font-style: italic;">c</span></sub>≈5  K</span>. We find that for both compounds the Fermi surface topology is in good agreement with density functional band-structure calculations and has almost nested electron an...</p><br/>[Phys. Rev. Lett. 108, 047002] Published Thu Jan 26, 2012 Author(s): C. Putzke, A. I. Coldea, I. Guillamón, D. Vignolles, A. McCollam, D. LeBoeuf, M. D. Watson, I. I. Mazin, S. Kasahara, T. Terashima, T. Shibauchi, Y. Matsuda, and A. Carrington

We report a de Haas–van Alphen oscillation study of the 111 iron pnictide superconductors LiFeAs with Tc≈18  K and LiFeP with Tc≈5  K. We find that for both compounds the Fermi surface topology is in good agreement with density functional band-structure calculations and has almost nested electron an...

[Phys. Rev. Lett. 108, 047002] Published Thu Jan 26, 2012

]]> de Haas–van Alphen Study of the Fermi Surfaces of Superconducting LiFeP and LiFeAs C. Putzke, A. I. Coldea, I. Guillamón, D. Vignolles, A. McCollam, D. LeBoeuf, M. D. Watson, I. I. Mazin, S. Kasahara, T. Terashima, T. Shibauchi, Y. Matsuda, and A. Carrington 2012-01-26T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevLett.108.047002 Phys. Rev. Lett. 108, 047002 (2012) article Physical Review Letters 108 4 2012-01-26T10:00:00-05:00 10.1103/PhysRevLett.108.047002 http://link.aps.org/doi/10.1103/PhysRevLett.108.047002 047002 Condensed Matter: Electronic Properties, etc. Condensed Matter: Electronic Properties, etc. Preemptive nematic order, pseudogap, and orbital order in the iron pnictides http://link.aps.org/doi/10.1103/PhysRevB.85.024534 Author(s): R. M. Fernandes, A. V. Chubukov, J. Knolle, I. Eremin, and J. Schmalian<br/><p>Starting from a microscopic itinerant model, we derive and analyze the effective low-energy model for collective magnetic excitations in the iron pnictides. We show that the stripe magnetic order is generally preempted by an Ising-nematic order, which breaks <span><span style="font-style: italic;">C</span><sub>4</sub></span> lattice symmetry but preserves <span><span style="font-style: italic;">O</span>(3)</span> sp...</p><br/>[Phys. Rev. B 85, 024534] Published Wed Jan 25, 2012 Author(s): R. M. Fernandes, A. V. Chubukov, J. Knolle, I. Eremin, and J. Schmalian

Starting from a microscopic itinerant model, we derive and analyze the effective low-energy model for collective magnetic excitations in the iron pnictides. We show that the stripe magnetic order is generally preempted by an Ising-nematic order, which breaks C4 lattice symmetry but preserves O(3) sp...

[Phys. Rev. B 85, 024534] Published Wed Jan 25, 2012

]]> Preemptive nematic order, pseudogap, and orbital order in the iron pnictides R. M. Fernandes, A. V. Chubukov, J. Knolle, I. Eremin, and J. Schmalian 2012-01-25T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024534 Phys. Rev. B 85, 024534 (2012) article Physical Review B 85 2 2012-01-25T10:00:00-05:00 10.1103/PhysRevB.85.024534 http://link.aps.org/doi/10.1103/PhysRevB.85.024534 024534 Superfluidity and superconductivity Superfluidity and superconductivity Conventional superconductivity in SrPd_{2}Ge_{2} http://link.aps.org/doi/10.1103/PhysRevB.85.014520 Author(s): T. K. Kim, A. N. Yaresko, V. B. Zabolotnyy, A. A. Kordyuk, D. V. Evtushinsky, N. H. Sung, B. K. Cho, T. Samuely, P. Szabó, J. G. Rodrigo, J. T. Park, D. S. Inosov, P. Samuely, B. Büchner, and S. V. Borisenko<br/><p>The electronic structure of SrPd<span><sub>2</sub></span>Ge<span><sub>2</sub></span> single crystals is studied by angle-resolved photoemission spectroscopy (ARPES), scanning tunneling spectroscopy (STS), and band structure calculations within the local-density approximation (LDA). The STS measurements show a single <span><span style="font-style: italic;">s</span></span>-wave superconducting energy ...</p><br/>[Phys. Rev. B 85, 014520] Published Wed Jan 25, 2012 Author(s): T. K. Kim, A. N. Yaresko, V. B. Zabolotnyy, A. A. Kordyuk, D. V. Evtushinsky, N. H. Sung, B. K. Cho, T. Samuely, P. Szabó, J. G. Rodrigo, J. T. Park, D. S. Inosov, P. Samuely, B. Büchner, and S. V. Borisenko

The electronic structure of SrPd2Ge2 single crystals is studied by angle-resolved photoemission spectroscopy (ARPES), scanning tunneling spectroscopy (STS), and band structure calculations within the local-density approximation (LDA). The STS measurements show a single s-wave superconducting energy ...

[Phys. Rev. B 85, 014520] Published Wed Jan 25, 2012

]]> Conventional superconductivity in SrPd_{2}Ge_{2} T. K. Kim, A. N. Yaresko, V. B. Zabolotnyy, A. A. Kordyuk, D. V. Evtushinsky, N. H. Sung, B. K. Cho, T. Samuely, P. Szabó, J. G. Rodrigo, J. T. Park, D. S. Inosov, P. Samuely, B. Büchner, and S. V. Borisenko 2012-01-25T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.014520 Phys. Rev. B 85, 014520 (2012) article Physical Review B 85 1 2012-01-25T10:00:00-05:00 10.1103/PhysRevB.85.014520 http://link.aps.org/doi/10.1103/PhysRevB.85.014520 014520 Superfluidity and superconductivity Superfluidity and superconductivity Pairing symmetries of a hole-doped extended two-orbital model for the pnictides http://link.aps.org/doi/10.1103/PhysRevB.85.024532 Author(s): Andrew Nicholson, Weihao Ge, José Riera, Maria Daghofer, Adriana Moreo, and Elbio Dagotto<br/><p>The hole-doped ground state of a recently introduced extended “<span><span style="font-style: italic;">t</span></span>-<span><span style="font-style: italic;">U</span></span>-<span><span style="font-style: italic;">J</span></span>” two-orbital Hubbard model for the Fe-based superconductors is studied via exact diagonalization methods on small clusters. Similarly as in the previously studied case of electron doping [ A. Nicholson <span style="font-style: italic;">et al.</span> <a href="http://dx.doi.org/10.1103/PhysRevLett.106.217002"> Phys. Rev. Lett. <span style="font-weight: bold;">106</span> ...</a></p><br/>[Phys. Rev. B 85, 024532] Published Tue Jan 24, 2012 Author(s): Andrew Nicholson, Weihao Ge, José Riera, Maria Daghofer, Adriana Moreo, and Elbio Dagotto

The hole-doped ground state of a recently introduced extended “t-U-J” two-orbital Hubbard model for the Fe-based superconductors is studied via exact diagonalization methods on small clusters. Similarly as in the previously studied case of electron doping [ A. Nicholson et al. Phys. Rev. Lett. 106 ...

[Phys. Rev. B 85, 024532] Published Tue Jan 24, 2012

]]> Pairing symmetries of a hole-doped extended two-orbital model for the pnictides Andrew Nicholson, Weihao Ge, José Riera, Maria Daghofer, Adriana Moreo, and Elbio Dagotto 2012-01-24T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024532 Phys. Rev. B 85, 024532 (2012) article Physical Review B 85 2 2012-01-24T10:00:00-05:00 10.1103/PhysRevB.85.024532 http://link.aps.org/doi/10.1103/PhysRevB.85.024532 024532 Superfluidity and superconductivity Superfluidity and superconductivity Theory of quasiparticle vortex bound states in iron-based superconductors: Application to scanning tunneling spectroscopy of LiFeAs http://link.aps.org/doi/10.1103/PhysRevB.85.020506 Author(s): Yan Wang, Peter J. Hirschfeld, and Ilya Vekhter<br/><p>The spectroscopy of vortex bound states can provide valuable information on the structure of the superconducting order parameter. Quasiparticle wave functions are expected to leak out in the directions of gap minima or nodes, if they exist, and scanning tunneling spectroscopy (STS) on these low-ener...</p><br/><img src="http://publish.aps.org/images/icons/rapid30x30.gif" width="30" height="30" alt="Rapid Communication"/> <br/>[Phys. Rev. B 85, 020506] Published Tue Jan 24, 2012 Author(s): Yan Wang, Peter J. Hirschfeld, and Ilya Vekhter

Rapid Communication The spectroscopy of vortex bound states can provide valuable information on the structure of the superconducting order parameter. Quasiparticle wave functions are expected to leak out in the directions of gap minima or nodes, if they exist, and scanning tunneling spectroscopy (STS) on these low-ener...

[Phys. Rev. B 85, 020506] Published Tue Jan 24, 2012

]]> Theory of quasiparticle vortex bound states in iron-based superconductors: Application to scanning tunneling spectroscopy of LiFeAs Yan Wang, Peter J. Hirschfeld, and Ilya Vekhter 2012-01-24T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.020506 Phys. Rev. B 85, 020506 (2012) article Physical Review B 85 2 2012-01-24T10:00:00-05:00 10.1103/PhysRevB.85.020506 http://link.aps.org/doi/10.1103/PhysRevB.85.020506 020506 Superfluidity and superconductivity Superfluidity and superconductivity Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe_{2}As_{2} http://link.aps.org/doi/10.1103/PhysRevB.85.024530 Author(s): H. Xiao, T. Hu, A. P. Dioguardi, N. apRoberts-Warren, A. C. Shockley, J. Crocker, D. M. Nisson, Z. Viskadourakis, Xianyang Tee, I. Radulov, C. C. Almasan, N. J. Curro, and C. Panagopoulos<br/><p>Resistivity, magnetization, and microscopic <span><sup>75</sup></span>As nuclear magnetic resonance (NMR) measurements in the antiferromagnetically ordered state of the iron-based superconductor parent material CaFe<span><sub>2</sub></span>As<span><sub>2</sub></span> exhibit anomalous features that are consistent with the collective freezing of domain walls. Below <span><span style="font-style: italic;">T</span><sup>*</sup>≈10</span>...</p><br/><img src="http://publish.aps.org/images/icons/prbsugg30x30.jpg" alt="PRB Editors' Suggestion"/> <br/>[Phys. Rev. B 85, 024530] Published Mon Jan 23, 2012 Author(s): H. Xiao, T. Hu, A. P. Dioguardi, N. apRoberts-Warren, A. C. Shockley, J. Crocker, D. M. Nisson, Z. Viskadourakis, Xianyang Tee, I. Radulov, C. C. Almasan, N. J. Curro, and C. Panagopoulos

PRB Editors' Suggestion Resistivity, magnetization, and microscopic 75As nuclear magnetic resonance (NMR) measurements in the antiferromagnetically ordered state of the iron-based superconductor parent material CaFe2As2 exhibit anomalous features that are consistent with the collective freezing of domain walls. Below T*≈10...

[Phys. Rev. B 85, 024530] Published Mon Jan 23, 2012

]]> Evidence for filamentary superconductivity nucleated at antiphase domain walls in antiferromagnetic CaFe_{2}As_{2} H. Xiao, T. Hu, A. P. Dioguardi, N. apRoberts-Warren, A. C. Shockley, J. Crocker, D. M. Nisson, Z. Viskadourakis, Xianyang Tee, I. Radulov, C. C. Almasan, N. J. Curro, and C. Panagopoulos 2012-01-23T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024530 Phys. Rev. B 85, 024530 (2012) article Physical Review B 85 2 2012-01-23T10:00:00-05:00 10.1103/PhysRevB.85.024530 http://link.aps.org/doi/10.1103/PhysRevB.85.024530 024530 Superfluidity and superconductivity Superfluidity and superconductivity Low-energy quasiparticles probed by heat transport in the iron-based superconductor LaFePO http://link.aps.org/doi/10.1103/PhysRevB.85.014517 Author(s): Mike Sutherland, J. Dunn, W. H. Toews, Eoin O’Farrell, James Analytis, Ian Fisher, and R. W. Hill<br/><p>We have measured the thermal conductivity of the iron pnictide superconductor LaFePO down to temperatures as low as <span><span style="font-style: italic;">T</span>=60</span> mK and in magnetic fields up to 5 T. The data show a large residual contribution that is linear in temperature, consistent with the presence of low-energy electronic quasiparticle...</p><br/>[Phys. Rev. B 85, 014517] Published Mon Jan 23, 2012 Author(s): Mike Sutherland, J. Dunn, W. H. Toews, Eoin O’Farrell, James Analytis, Ian Fisher, and R. W. Hill

We have measured the thermal conductivity of the iron pnictide superconductor LaFePO down to temperatures as low as T=60 mK and in magnetic fields up to 5 T. The data show a large residual contribution that is linear in temperature, consistent with the presence of low-energy electronic quasiparticle...

[Phys. Rev. B 85, 014517] Published Mon Jan 23, 2012

]]> Low-energy quasiparticles probed by heat transport in the iron-based superconductor LaFePO Mike Sutherland, J. Dunn, W. H. Toews, Eoin O’Farrell, James Analytis, Ian Fisher, and R. W. Hill 2012-01-23T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.014517 Phys. Rev. B 85, 014517 (2012) article Physical Review B 85 1 2012-01-23T10:00:00-05:00 10.1103/PhysRevB.85.014517 http://link.aps.org/doi/10.1103/PhysRevB.85.014517 014517 Superfluidity and superconductivity Superfluidity and superconductivity Unconventional Anisotropic s-Wave Superconducting Gaps of the LiFeAs Iron-Pnictide Superconductor http://link.aps.org/doi/10.1103/PhysRevLett.108.037002 Author(s): K. Umezawa, Y. Li, H. Miao, K. Nakayama, Z.-H. Liu, P. Richard, T. Sato, J. B. He, D.-M. Wang, G. F. Chen, H. Ding, T. Takahashi, and S.-C. Wang<br/><p>We have performed high-resolution angle-resolved photoemission spectroscopy on Fe-based superconductor LiFeAs (<span><span style="font-style: italic;">T</span><sub><span style="font-style: italic;">c</span></sub>=18  K</span>). We reveal multiple nodeless superconducting (SC) gaps with <span>2<span style="font-style: italic;">Δ</span>/<span style="font-style: italic;">k</span><sub><span style="font-style: italic;">B</span></sub><span style="font-style: italic;">T</span><sub><span style="font-style: italic;">c</span></sub></span> ratios varying from 2.8 to 6.4, depending on the Fermi surface (FS). We also succeeded in directly observing a ...</p><br/>[Phys. Rev. Lett. 108, 037002] Published Fri Jan 20, 2012 Author(s): K. Umezawa, Y. Li, H. Miao, K. Nakayama, Z.-H. Liu, P. Richard, T. Sato, J. B. He, D.-M. Wang, G. F. Chen, H. Ding, T. Takahashi, and S.-C. Wang

We have performed high-resolution angle-resolved photoemission spectroscopy on Fe-based superconductor LiFeAs (Tc=18  K). We reveal multiple nodeless superconducting (SC) gaps with 2Δ/kBTc ratios varying from 2.8 to 6.4, depending on the Fermi surface (FS). We also succeeded in directly observing a ...

[Phys. Rev. Lett. 108, 037002] Published Fri Jan 20, 2012

]]> Unconventional Anisotropic s-Wave Superconducting Gaps of the LiFeAs Iron-Pnictide Superconductor K. Umezawa, Y. Li, H. Miao, K. Nakayama, Z.-H. Liu, P. Richard, T. Sato, J. B. He, D.-M. Wang, G. F. Chen, H. Ding, T. Takahashi, and S.-C. Wang 2012-01-20T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevLett.108.037002 Phys. Rev. Lett. 108, 037002 (2012) article Physical Review Letters 108 3 2012-01-20T10:00:00-05:00 10.1103/PhysRevLett.108.037002 http://link.aps.org/doi/10.1103/PhysRevLett.108.037002 037002 Condensed Matter: Electronic Properties, etc. Condensed Matter: Electronic Properties, etc. Structural analysis and superconductivity of CeFeAsO_{1−x}H_{x} http://link.aps.org/doi/10.1103/PhysRevB.85.014514 Author(s): Satoru Matsuishi, Taku Hanna, Yoshinori Muraba, Sung Wng Kim, Jung Eun Kim, Masaki Takata, Shin-ich Shamoto, Ronald I. Smith, and Hideo Hosono<br/><p>We performed the neutron powder diffraction (NPD) and synchrotron x-ray diffraction measurements on CeFeAsO<span><sub>1−<span style="font-style: italic;">x</span></sub></span>(D,H)<span><sub><span style="font-style: italic;">x</span></sub></span> (<span><span style="font-style: italic;">x</span></span> <span>=</span> 0.0 − 0.48) as a representative of 1111-type family of iron-based superconductors <span><span style="font-style: italic;">L</span><span style="font-style: italic;">n</span></span>FeAsO<span><sub>1−<span style="font-style: italic;">x</span></sub></span>H<span><sub><span style="font-style: italic;">x</span></sub></span> (<span><span style="font-style: italic;">L</span><span style="font-style: italic;">n</span></span> <span>=</span> lanthanoid). Deuterated and hydrogenated samples (CeFeAsO<span><sub>1−<span style="font-style: italic;">x</span></sub></span>D<span><sub><span style="font-style: italic;">x</span></sub></span> and CeFeAsO<span><sub>1−<span style="font-style: italic;">x</span></sub></span>...</p><br/><img src="http://publish.aps.org/images/icons/prbsugg30x30.jpg" alt="PRB Editors' Suggestion"/> <br/>[Phys. Rev. B 85, 014514] Published Thu Jan 19, 2012 Author(s): Satoru Matsuishi, Taku Hanna, Yoshinori Muraba, Sung Wng Kim, Jung Eun Kim, Masaki Takata, Shin-ich Shamoto, Ronald I. Smith, and Hideo Hosono

PRB Editors' Suggestion We performed the neutron powder diffraction (NPD) and synchrotron x-ray diffraction measurements on CeFeAsO1−x(D,H)x (x = 0.0 − 0.48) as a representative of 1111-type family of iron-based superconductors LnFeAsO1−xHx (Ln = lanthanoid). Deuterated and hydrogenated samples (CeFeAsO1−xDx and CeFeAsO1−x...

[Phys. Rev. B 85, 014514] Published Thu Jan 19, 2012

]]> Structural analysis and superconductivity of CeFeAsO_{1−x}H_{x} Satoru Matsuishi, Taku Hanna, Yoshinori Muraba, Sung Wng Kim, Jung Eun Kim, Masaki Takata, Shin-ich Shamoto, Ronald I. Smith, and Hideo Hosono 2012-01-19T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.014514 Phys. Rev. B 85, 014514 (2012) article Physical Review B 85 1 2012-01-19T10:00:00-05:00 10.1103/PhysRevB.85.014514 http://link.aps.org/doi/10.1103/PhysRevB.85.014514 014514 Superfluidity and superconductivity Superfluidity and superconductivity Gutzwiller Theory of Band Magnetism in LaOFeAs http://link.aps.org/doi/10.1103/PhysRevLett.108.036406 Author(s): Tobias Schickling, Florian Gebhard, Jörg Bünemann, Lilia Boeri, Ole K. Andersen, and Werner Weber<br/><p>We use the Gutzwiller variational theory to calculate the ground-state phase diagram and quasiparticle bands of LaOFeAs. The <span>Fe3d-As4p</span> Wannier-orbital basis obtained from density-functional theory defines the band part of our eight-band Hubbard model. The full atomic interaction between the electron...</p><br/>[Phys. Rev. Lett. 108, 036406] Published Thu Jan 19, 2012 Author(s): Tobias Schickling, Florian Gebhard, Jörg Bünemann, Lilia Boeri, Ole K. Andersen, and Werner Weber

We use the Gutzwiller variational theory to calculate the ground-state phase diagram and quasiparticle bands of LaOFeAs. The Fe3d-As4p Wannier-orbital basis obtained from density-functional theory defines the band part of our eight-band Hubbard model. The full atomic interaction between the electron...

[Phys. Rev. Lett. 108, 036406] Published Thu Jan 19, 2012

]]> Gutzwiller Theory of Band Magnetism in LaOFeAs Tobias Schickling, Florian Gebhard, Jörg Bünemann, Lilia Boeri, Ole K. Andersen, and Werner Weber 2012-01-19T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevLett.108.036406 Phys. Rev. Lett. 108, 036406 (2012) article Physical Review Letters 108 3 2012-01-19T10:00:00-05:00 10.1103/PhysRevLett.108.036406 http://link.aps.org/doi/10.1103/PhysRevLett.108.036406 036406 Condensed Matter: Electronic Properties, etc. Condensed Matter: Electronic Properties, etc. Doping-dependent superconducting gap anisotropy in the two-dimensional pnictide Ca_{10}(Pt_{3}As_{8})[(Fe_{1-x}Pt_{x})_{2}As_{2}]_{5} http://link.aps.org/doi/10.1103/PhysRevB.85.020504 Author(s): K. Cho, M. A. Tanatar, H. Kim, W. E. Straszheim, N. Ni, R. J. Cava, and R. Prozorov<br/><p>The characteristic features of the Ca<span><sub>10</sub></span>(Pt<span><sub>3</sub></span>As<span><sub>8</sub></span>)[(Fe<span><sub>1-<span style="font-style: italic;">x</span></sub></span>Pt<span><sub><span style="font-style: italic;">x</span></sub></span>)<span><sub>2</sub></span>As<span><sub>2</sub></span>]<span><sub>5</sub></span> (the “10-3-8” phase) superconductor are triclinic symmetry, high anisotropy, and a clear separation of superconducting and antiferromagnetic regions in the <span><span style="font-style: italic;">T</span></span> versus doping (<span><span style="font-style: italic;">x</span></span>) phase diagram, which enables the superconducting gap to be ...</p><br/><img src="http://publish.aps.org/images/icons/prbsugg30x30.jpg" alt="PRB Editors' Suggestion"/> <img src="http://publish.aps.org/images/icons/rapid30x30.gif" width="30" height="30" alt="Rapid Communication"/> <br/>[Phys. Rev. B 85, 020504] Published Wed Jan 18, 2012 Author(s): K. Cho, M. A. Tanatar, H. Kim, W. E. Straszheim, N. Ni, R. J. Cava, and R. Prozorov

PRB Editors' Suggestion Rapid Communication The characteristic features of the Ca10(Pt3As8)[(Fe1-xPtx)2As2]5 (the “10-3-8” phase) superconductor are triclinic symmetry, high anisotropy, and a clear separation of superconducting and antiferromagnetic regions in the T versus doping (x) phase diagram, which enables the superconducting gap to be ...

[Phys. Rev. B 85, 020504] Published Wed Jan 18, 2012

]]> Doping-dependent superconducting gap anisotropy in the two-dimensional pnictide Ca_{10}(Pt_{3}As_{8})[(Fe_{1-x}Pt_{x})_{2}As_{2}]_{5} K. Cho, M. A. Tanatar, H. Kim, W. E. Straszheim, N. Ni, R. J. Cava, and R. Prozorov 2012-01-18T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.020504 Phys. Rev. B 85, 020504 (2012) article Physical Review B 85 2 2012-01-18T10:00:00-05:00 10.1103/PhysRevB.85.020504 http://link.aps.org/doi/10.1103/PhysRevB.85.020504 020504 Superfluidity and superconductivity Superfluidity and superconductivity Evolution of normal and superconducting properties of single crystals of Na_{1–δ}FeAs upon interaction with environment http://link.aps.org/doi/10.1103/PhysRevB.85.014510 Author(s): M. A. Tanatar, N. Spyrison, Kyuil Cho, E. C. Blomberg, Guotai Tan, Pengcheng Dai, Chenglin Zhang, and R. Prozorov<br/><p>Iron-arsenide superconductor Na<span><sub>1–<span style="font-style: italic;">δ</span></sub></span>FeAs is highly reactive with the environment. Due to the high mobility of Na ions, this reaction affects the entire bulk of the crystals and leads to an effective stoichiometry change. Here we use this effect to study the doping evolution of normal and superconducti...</p><br/>[Phys. Rev. B 85, 014510] Published Wed Jan 18, 2012 Author(s): M. A. Tanatar, N. Spyrison, Kyuil Cho, E. C. Blomberg, Guotai Tan, Pengcheng Dai, Chenglin Zhang, and R. Prozorov

Iron-arsenide superconductor Na1–δFeAs is highly reactive with the environment. Due to the high mobility of Na ions, this reaction affects the entire bulk of the crystals and leads to an effective stoichiometry change. Here we use this effect to study the doping evolution of normal and superconducti...

[Phys. Rev. B 85, 014510] Published Wed Jan 18, 2012

]]> Evolution of normal and superconducting properties of single crystals of Na_{1–δ}FeAs upon interaction with environment M. A. Tanatar, N. Spyrison, Kyuil Cho, E. C. Blomberg, Guotai Tan, Pengcheng Dai, Chenglin Zhang, and R. Prozorov 2012-01-18T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.014510 Phys. Rev. B 85, 014510 (2012) article Physical Review B 85 1 2012-01-18T10:00:00-05:00 10.1103/PhysRevB.85.014510 http://link.aps.org/doi/10.1103/PhysRevB.85.014510 014510 Superfluidity and superconductivity Superfluidity and superconductivity Gap symmetry in KFe_{2}As_{2} and the cos 4θ gap component in LiFeAs http://link.aps.org/doi/10.1103/PhysRevB.85.014511 Author(s): S. Maiti, M. M. Korshunov, and A. V. Chubukov<br/><p>We revisit the issue of the gap symmetry in KFe<span><sub>2</sub></span>As<span><sub>2</sub></span>, which is an Fe pnictide superconductor with only hole pockets. Previous theoretical studies mostly argued for a <span><span style="font-style: italic;">d</span>-</span>wave gap in KFe<span><sub>2</sub></span>As<span><sub>2</sub></span> since transport and thermodynamic measurements point to the presence of the gap nodes. However, a <span><span style="font-style: italic;">d</span></span>-wave gap is i...</p><br/>[Phys. Rev. B 85, 014511] Published Wed Jan 18, 2012 Author(s): S. Maiti, M. M. Korshunov, and A. V. Chubukov

We revisit the issue of the gap symmetry in KFe2As2, which is an Fe pnictide superconductor with only hole pockets. Previous theoretical studies mostly argued for a d-wave gap in KFe2As2 since transport and thermodynamic measurements point to the presence of the gap nodes. However, a d-wave gap is i...

[Phys. Rev. B 85, 014511] Published Wed Jan 18, 2012

]]> Gap symmetry in KFe_{2}As_{2} and the cos 4θ gap component in LiFeAs S. Maiti, M. M. Korshunov, and A. V. Chubukov 2012-01-18T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.014511 Phys. Rev. B 85, 014511 (2012) article Physical Review B 85 1 2012-01-18T10:00:00-05:00 10.1103/PhysRevB.85.014511 http://link.aps.org/doi/10.1103/PhysRevB.85.014511 014511 Superfluidity and superconductivity Superfluidity and superconductivity Structural phase transitions in SrRh_{2}As_{2} http://link.aps.org/doi/10.1103/PhysRevB.85.014109 Author(s): V. Zinth, V. Petricek, M. Dusek, and D. Johrendt<br/><p>SrRh<span><sub>2</sub></span>As<span><sub>2</sub></span> crystallizes with three polymorphs derived from the tetragonal ThCr<span><sub>2</sub></span>Si<span><sub>2</sub></span>-type structure and exhibits structural phase transitions comparable to those of BaFe<span><sub>2</sub></span>As<span><sub>2</sub></span>, a parent compound of iron-based superconductors. The structure of <span><span style="font-style: italic;">α</span></span>-SrRh<span><sub>2</sub></span>As<span><sub>2</sub></span> is monoclinic (<span><span style="font-style: italic;">a</span>=421.2(1)</span> pm, <span><span style="font-style: italic;">b</span>=1105.6(2)</span> pm, <span><span style="font-style: italic;">c</span></span> = 84...</p><br/>[Phys. Rev. B 85, 014109] Published Tue Jan 17, 2012 Author(s): V. Zinth, V. Petricek, M. Dusek, and D. Johrendt

SrRh2As2 crystallizes with three polymorphs derived from the tetragonal ThCr2Si2-type structure and exhibits structural phase transitions comparable to those of BaFe2As2, a parent compound of iron-based superconductors. The structure of α-SrRh2As2 is monoclinic (a=421.2(1) pm, b=1105.6(2) pm, c = 84...

[Phys. Rev. B 85, 014109] Published Tue Jan 17, 2012

]]> Structural phase transitions in SrRh_{2}As_{2} V. Zinth, V. Petricek, M. Dusek, and D. Johrendt 2012-01-17T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.014109 Phys. Rev. B 85, 014109 (2012) article Physical Review B 85 1 2012-01-17T10:00:00-05:00 10.1103/PhysRevB.85.014109 http://link.aps.org/doi/10.1103/PhysRevB.85.014109 014109 Structure, structural phase transitions, mechanical properties, defects Structure, structural phase transitions, mechanical properties, defects Structural collapse and superconductivity in rare-earth-doped CaFe_{2}As_{2} http://link.aps.org/doi/10.1103/PhysRevB.85.024525 Author(s): S. R. Saha, N. P. Butch, T. Drye, J. Magill, S. Ziemak, K. Kirshenbaum, P. Y. Zavalij, J. W. Lynn, and J. Paglione<br/><p>Aliovalent rare-earth substitution into the alkaline-earth site of CaFe<span><sub>2</sub></span>As<span><sub>2</sub></span> single crystals is used to fine tune structural, magnetic, and electronic properties of this iron-based superconducting system. Neutron and single-crystal x-ray scattering experiments indicate that an isostructural collapse ...</p><br/>[Phys. Rev. B 85, 024525] Published Fri Jan 13, 2012 Author(s): S. R. Saha, N. P. Butch, T. Drye, J. Magill, S. Ziemak, K. Kirshenbaum, P. Y. Zavalij, J. W. Lynn, and J. Paglione

Aliovalent rare-earth substitution into the alkaline-earth site of CaFe2As2 single crystals is used to fine tune structural, magnetic, and electronic properties of this iron-based superconducting system. Neutron and single-crystal x-ray scattering experiments indicate that an isostructural collapse ...

[Phys. Rev. B 85, 024525] Published Fri Jan 13, 2012

]]> Structural collapse and superconductivity in rare-earth-doped CaFe_{2}As_{2} S. R. Saha, N. P. Butch, T. Drye, J. Magill, S. Ziemak, K. Kirshenbaum, P. Y. Zavalij, J. W. Lynn, and J. Paglione 2012-01-13T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024525 Phys. Rev. B 85, 024525 (2012) article Physical Review B 85 2 2012-01-13T10:00:00-05:00 10.1103/PhysRevB.85.024525 http://link.aps.org/doi/10.1103/PhysRevB.85.024525 024525 Superfluidity and superconductivity Superfluidity and superconductivity Raman scattering study of the lattice dynamics of superconducting LiFeAs http://link.aps.org/doi/10.1103/PhysRevB.85.012501 Author(s): Y. J. Um, J. T. Park, B. H. Min, Y. J. Song, Y. S. Kwon, B. Keimer, and M. Le Tacon<br/><p>We report an investigation of the lattice dynamical properties of LiFeAs using inelastic light scattering. Five of the six expected phonon modes are observed. The temperature evolution of their frequencies and linewidths is in good agreement with an anharmonic-decay model. We find no evidence for su...</p><br/>[Phys. Rev. B 85, 012501] Published Thu Jan 12, 2012 Author(s): Y. J. Um, J. T. Park, B. H. Min, Y. J. Song, Y. S. Kwon, B. Keimer, and M. Le Tacon

We report an investigation of the lattice dynamical properties of LiFeAs using inelastic light scattering. Five of the six expected phonon modes are observed. The temperature evolution of their frequencies and linewidths is in good agreement with an anharmonic-decay model. We find no evidence for su...

[Phys. Rev. B 85, 012501] Published Thu Jan 12, 2012

]]> Raman scattering study of the lattice dynamics of superconducting LiFeAs Y. J. Um, J. T. Park, B. H. Min, Y. J. Song, Y. S. Kwon, B. Keimer, and M. Le Tacon 2012-01-12T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.012501 Phys. Rev. B 85, 012501 (2012) article Physical Review B 85 1 2012-01-12T10:00:00-05:00 10.1103/PhysRevB.85.012501 http://link.aps.org/doi/10.1103/PhysRevB.85.012501 012501 Superfluidity and superconductivity Superfluidity and superconductivity Vacancy ordering and phonon spectrum of the iron-based superconductor K_{0.8}Fe_{1.6}Se_{2} http://link.aps.org/doi/10.1103/PhysRevB.85.024518 Author(s): A. M. Zhang, K. Liu, J. H. Xiao, J. B. He, D. M. Wang, G. F. Chen, B. Normand, and Q. M. Zhang<br/><p>We have performed Raman-scattering measurements on a high-quality single crystal of the recently discovered Fe-based superconductor K<span><sub>0.8</sub></span>Fe<span><sub>1.6</sub></span>Se<span><sub>2</sub></span> (<span><span style="font-style: italic;">T</span><sub><span style="font-style: italic;">c</span></sub></span> <span><span style="font-style: italic;">=</span></span> 32 K). At least 13 phonon modes were observed in the wave number range 10–300 cm<span><sup>−1</sup></span>. The spectra possess a fourfold symmetry indicative of bulk vacanc...</p><br/>[Phys. Rev. B 85, 024518] Published Wed Jan 11, 2012 Author(s): A. M. Zhang, K. Liu, J. H. Xiao, J. B. He, D. M. Wang, G. F. Chen, B. Normand, and Q. M. Zhang

We have performed Raman-scattering measurements on a high-quality single crystal of the recently discovered Fe-based superconductor K0.8Fe1.6Se2 (Tc = 32 K). At least 13 phonon modes were observed in the wave number range 10–300 cm−1. The spectra possess a fourfold symmetry indicative of bulk vacanc...

[Phys. Rev. B 85, 024518] Published Wed Jan 11, 2012

]]> Vacancy ordering and phonon spectrum of the iron-based superconductor K_{0.8}Fe_{1.6}Se_{2} A. M. Zhang, K. Liu, J. H. Xiao, J. B. He, D. M. Wang, G. F. Chen, B. Normand, and Q. M. Zhang 2012-01-11T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024518 Phys. Rev. B 85, 024518 (2012) article Physical Review B 85 2 2012-01-11T10:00:00-05:00 10.1103/PhysRevB.85.024518 http://link.aps.org/doi/10.1103/PhysRevB.85.024518 024518 Superfluidity and superconductivity Superfluidity and superconductivity Signatures of quantum criticality in hole-doped and chemically pressurized EuFe_{2}As_{2} single crystals http://link.aps.org/doi/10.1103/PhysRevB.85.024511 Author(s): Jannis Maiwald, H. S. Jeevan, and Philipp Gegenwart<br/><p>We study the effect of hole doping and chemical pressure (isovalent doping) in single crystals of K<span><sub><span style="font-style: italic;">x</span></sub></span>Eu<span><sub>1−<span style="font-style: italic;">x</span></sub></span>Fe<span><sub>2</sub></span>As<span><sub>2</sub></span> and EuFe<span><sub>2</sub></span>(As<span><sub>1−<span style="font-style: italic;">y</span></sub></span>P<span><sub><span style="font-style: italic;">y</span></sub></span>)<span><sub>2</sub></span>, respectively, by measuring the thermopower, <span><span style="font-style: italic;">S</span>(<span style="font-style: italic;">T</span>)</span>, and electrical resistivity, <span><span style="font-style: italic;">ρ</span>(<span style="font-style: italic;">T</span>)</span>. The evolution of <span><span style="font-style: italic;">S</span>(<span style="font-style: italic;">T</span>)</span> upon doping indicates drastic changes in the electronic confi...</p><br/>[Phys. Rev. B 85, 024511] Published Thu Jan 05, 2012 Author(s): Jannis Maiwald, H. S. Jeevan, and Philipp Gegenwart

We study the effect of hole doping and chemical pressure (isovalent doping) in single crystals of KxEu1−xFe2As2 and EuFe2(As1−yPy)2, respectively, by measuring the thermopower, S(T), and electrical resistivity, ρ(T). The evolution of S(T) upon doping indicates drastic changes in the electronic confi...

[Phys. Rev. B 85, 024511] Published Thu Jan 05, 2012

]]> Signatures of quantum criticality in hole-doped and chemically pressurized EuFe_{2}As_{2} single crystals Jannis Maiwald, H. S. Jeevan, and Philipp Gegenwart 2012-01-05T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024511 Phys. Rev. B 85, 024511 (2012) article Physical Review B 85 2 2012-01-05T10:00:00-05:00 10.1103/PhysRevB.85.024511 http://link.aps.org/doi/10.1103/PhysRevB.85.024511 024511 Superfluidity and superconductivity Superfluidity and superconductivity Effect of molybdenum 4d hole substitution in BaFe_{2}As_{2} http://link.aps.org/doi/10.1103/PhysRevB.85.024503 Author(s): Athena S. Sefat, Karol Marty, Andrew D. Christianson, Bayrammurad Saparov, Michael A. McGuire, Mark D. Lumsden, Wei Tian, and Brian C. Sales<br/><p>We investigate the thermodynamic and transport properties of molybdenum-doped BaFe<span><sub>2</sub></span>As<span><sub>2</sub></span> (122) crystals, the first report of hole doping using a 4<span><span style="font-style: italic;">d</span></span> element. The chemical substitution of Mo in place of Fe is possible up to ∼ 7<span>%</span>. For Ba(Fe<span><sub>1-<span style="font-style: italic;">x</span></sub></span>Mo<span><sub><span style="font-style: italic;">x</span></sub></span>)<span><sub>2</sub></span>As<span><sub>2</sub></span>, the suppression rate of the magnetic transition temp...</p><br/>[Phys. Rev. B 85, 024503] Published Tue Jan 03, 2012 Author(s): Athena S. Sefat, Karol Marty, Andrew D. Christianson, Bayrammurad Saparov, Michael A. McGuire, Mark D. Lumsden, Wei Tian, and Brian C. Sales

We investigate the thermodynamic and transport properties of molybdenum-doped BaFe2As2 (122) crystals, the first report of hole doping using a 4d element. The chemical substitution of Mo in place of Fe is possible up to ∼ 7%. For Ba(Fe1-xMox)2As2, the suppression rate of the magnetic transition temp...

[Phys. Rev. B 85, 024503] Published Tue Jan 03, 2012

]]> Effect of molybdenum 4d hole substitution in BaFe_{2}As_{2} Athena S. Sefat, Karol Marty, Andrew D. Christianson, Bayrammurad Saparov, Michael A. McGuire, Mark D. Lumsden, Wei Tian, and Brian C. Sales 2012-01-03T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024503 Phys. Rev. B 85, 024503 (2012) article Physical Review B 85 2 2012-01-03T10:00:00-05:00 10.1103/PhysRevB.85.024503 http://link.aps.org/doi/10.1103/PhysRevB.85.024503 024503 Superfluidity and superconductivity Superfluidity and superconductivity Local structure of the superconductor K_{0.8}Fe_{1.6+x}Se_{2}: Evidence of large structural disorder http://link.aps.org/doi/10.1103/PhysRevB.85.024504 Author(s): T. A. Tyson, T. Yu, S. J. Han, M. Croft, G. D. Gu, I. K. Dimitrov, and Q. Li<br/><p>The local structure of superconducting single crystals of K<span><sub>0.8</sub></span>Fe<span><sub>1.6+<span style="font-style: italic;">x</span></sub></span>Se<span><sub>2</sub></span> with <span><span style="font-style: italic;">T</span><span style="font-style: italic;">c</span></span> <span>=</span> 32.6 K was studied by x-ray absorption spectroscopy. Near-edge spectra reveal that the average valence of Fe is 2+. The room temperature structure about the Fe, K, and Se sites was examined by iron, selenium, and pota...</p><br/>[Phys. Rev. B 85, 024504] Published Tue Jan 03, 2012 Author(s): T. A. Tyson, T. Yu, S. J. Han, M. Croft, G. D. Gu, I. K. Dimitrov, and Q. Li

The local structure of superconducting single crystals of K0.8Fe1.6+xSe2 with Tc = 32.6 K was studied by x-ray absorption spectroscopy. Near-edge spectra reveal that the average valence of Fe is 2+. The room temperature structure about the Fe, K, and Se sites was examined by iron, selenium, and pota...

[Phys. Rev. B 85, 024504] Published Tue Jan 03, 2012

]]> Local structure of the superconductor K_{0.8}Fe_{1.6+x}Se_{2}: Evidence of large structural disorder T. A. Tyson, T. Yu, S. J. Han, M. Croft, G. D. Gu, I. K. Dimitrov, and Q. Li 2012-01-03T10:00:00-05:00 Personal use only, all commercial or other reuse prohibited doi:10.1103/PhysRevB.85.024504 Phys. Rev. B 85, 024504 (2012) article Physical Review B 85 2 2012-01-03T10:00:00-05:00 10.1103/PhysRevB.85.024504 http://link.aps.org/doi/10.1103/PhysRevB.85.024504 024504 Superfluidity and superconductivity Superfluidity and superconductivity