Numerical simulations of previous plane shock wave measurements on highly oriented pyrolytic graphite (HOPG), shocked to four peak stresses ranging from 27 to 50 GPa, are presented to address a long-standing question: When is the diamond phase formed in the shock-compressed graphite to diamond trans...

[Phys. Rev. B 87, 174104] Published Fri May 17, 2013

Recent experimental progress in coupling nanoscale conductors to superconducting microwave cavities has opened up for transport investigations of the deep quantum limit of light-matter interactions, with tunneling electrons strongly coupled to individual cavity photons. We have investigated theoreti...

[Phys. Rev. B 87, 195427] Published Tue May 14, 2013

We report the observation of optical near fields in a photonic waveguide of conductive indium tin oxide (ITO) using multiphoton photoemission electron microscopy (PEEM). Nonlinear two-photon photoelectron emission is enhanced at field maxima created by interference between incident 410-nm and cohere...

[Phys. Rev. B 87, 205419] Published Mon May 13, 2013

The real-time dynamics of local occupation numbers in a Hubbard model on a 6×6 square lattice is studied by means of the nonequilibrium generalization of the cluster-perturbation theory. The cluster approach is adapted to studies of two-dimensional lattice systems by using concepts of multiple-scatt...

[Phys. Rev. B 87, 205118] Published Mon May 13, 2013

In Phys. Rev. Lett. 109 245502 (2012), a method for retrieving the object's three-dimensional potential distribution by inverting the dynamical scattering was presented and validated by a reconstruction from simulated atomic resolution transmission electron microscopy (TEM) images. In this paper, ...

[Phys. Rev. B 87, 184108] Published Mon May 13, 2013

We study the Landau-Zener dynamics of a tunneling spin coupled to a torsional resonator. For strong spin-phonon coupling, when the oscillator frequency is large compared to the tunnel splitting, the system exhibits multiple Landau-Zener transitions. Entanglement of spin and mechanical angular moment...

[Phys. Rev. B 87, 174418] Published Mon May 13, 2013

We report on a comparative study of spin Hall related effects and magnetoresistance in YIG|Pt and YIG|Ta bilayers. These combined measurements allow to estimate the characteristic transport parameters of both Pt and Ta layers juxtaposed to yttrium iron garnet (YIG): the spin mixing conductance G_↑↓ a...

[Phys. Rev. B 87, 174417] Published Mon May 13, 2013

We examine the influence of the main approximations employed in density functional theory descriptions of the solid phase of molecular hydrogen near dissociation. We consider the importance of nuclear quantum effects on equilibrium properties and find that they strongly influence intramolecular prop...

[Phys. Rev. B 87, 184107] Published Fri May 10, 2013

We present a study of free carrier photogeneration and multicarrier bound states, such as biexcitons and trions (charged excitons), in semiconducting single-walled carbon nanotubes. Pump-and-probe measurements performed with fs pulses reveal the effects of strong Coulomb interactions between carrier...

[Phys. Rev. B 87, 205412] Published Wed May 08, 2013

Motivated by the nickel valence controversy in the perovskite nickelate RNiO₃, we consider a one-dimensional underscreened Kondo chain consisting of alternating spin-1 (“nickel”) and electron (“oxygen”) sites, which in addition to the usual electron hopping and spin-spin interaction between the S=1 ...

[Phys. Rev. B 87, 205107] Published Wed May 08, 2013

ZrB₂ is a nonsuperconducting Pauli paramagnetic crystallizing in the AlB₂ structure. V substitution for Zr in Zr_1−xV_xB₂ (0.01 ≤ x ≤ 0.1) at the few percentage level induces superconductivity with critical temperature reaching a maximum of 8.7 K for Zr_0.96V_0.04B₂ near the solid solubility limit. Spec...

[Phys. Rev. B 87, 174502] Published Mon May 06, 2013

We apply grazing-incidence femtosecond x-ray diffraction to investigate the details of the atomic motion connected with a displacively excited coherent optical phonon. We concentrate on the low frequency phonon associated with the charge and orbital order in the mixed valence manganite La_0.25Pr_0.375...

[Phys. Rev. B 87, 205104] Published Fri May 03, 2013

The change in the electronic structure of layered Cu_xIrTe₂ has been characterized by transport and spectroscopic measurements, combined with first-principles calculations. The Cu intercalation suppresses the monoclinic distortion, giving rise to the stabilization of the trigonal phase with supercond...

[Phys. Rev. B 87, 180501] Published Thu May 02, 2013

Optical spectroscopy is performed for c-plane homoepitaxial aluminum nitride (AlN) films. The temperature dependence of the polarization-resolved photoluminescence spectra reveals the exciton fine structure. The experimental results demonstrate that the electron-hole exchange interaction energy (j) ...

[Phys. Rev. B 87, 161204] Published Tue Apr 30, 2013

We report local probe investigations of the magnetic interaction between BiFeO₃ films and a ferromagnetic Co_0.9Fe_0.1 layer. Within the constraints of intralayer exchange coupling in the Co_0.9Fe_0.1, the multiferroic imprint in the ferromagnet results in a collinear arrangement of the local magnetizat...

[Phys. Rev. B 87, 134426] Published Tue Apr 30, 2013

As a long-lived theme in solid-state physics, the Kondo effect reflects the many-body physics involving the short-range Coulomb interactions between itinerant electrons and localized spins in metallic materials. Here we show that the Kondo effect is present in ZnO, a prototypical wide-band-gap oxide...

[Phys. Rev. B 87, 155151] Published Mon Apr 29, 2013

We study the charge response of conformal field theories (CFTs) at nonzero temperature in 2+1 dimensions using the anti-de Sitter (AdS)/CFT correspondence. A central role is played by the quasinormal modes (QNMs), specifically, the poles and zeros of the current correlators. We generalize our recent...

[Phys. Rev. B 87, 155149] Published Mon Apr 29, 2013

We study a class of SU(N) Heisenberg models, describing Mott insulators of fermionic ultracold alkaline earth atoms on the three-dimensional simple cubic lattice. Based on an earlier semiclassical analysis, magnetic order is unlikely, and we focus instead on a solvable large-N limit designed to addr...

[Phys. Rev. B 87, 144423] Published Mon Apr 29, 2013

Electronic nematic phases have been proposed to occur in various correlated electron systems and were recently claimed to have been detected in scanning tunneling microscopy (STM) conductance maps of the pseudogap states of the cuprate high-temperature superconductor Bi₂Sr₂CaCu₂O_8+δ (Bi-2212). We in...

[Phys. Rev. B 87, 161117] Published Thu Apr 25, 2013

It is well known that the Haldane phase of a one-dimensional spin-1 chain is a symmetry-protected topological (SPT) phase, which is described by a nonlinear sigma model (NLSM) with a Θ term at Θ=2π. In this work we study a three-dimensional (3d) SPT phase of a SU(2N) antiferromagnetic spin system wi...

[Phys. Rev. B 87, 144421] Published Thu Apr 25, 2013

Topological superconductors are gapped superconductors with gapless and topologically robust quasiparticles propagating on the boundary. In this paper, we present a topological field theory description of three-dimensional time-reversal invariant topological superconductors. In our theory the topolo...

[Phys. Rev. B 87, 134519] Published Thu Apr 25, 2013

The thermally activated glide of screw dislocations in bcc crystals proceeds through the formation of kinks by pairs, a mechanism named after Peierls for his early work on dislocation theory. A method is proposed to compute the dislocation kink-pair formation enthalpy from density functional theory ...

[Phys. Rev. B 87, 144106] Published Tue Apr 23, 2013

We analyze the evolution of the superconducting gap structure in strongly hole-doped Ba_1−xK_xFe₂As₂ between x=1 and x∼0.4 (optimal doping). In the latter case, the pairing state is most likely s±, with different gap signs on hole and electron pockets, but with the same signs of the gap on the two Γ-c...

[Phys. Rev. B 87, 144511] Published Mon Apr 22, 2013

We show that the lack of inversion symmetry in monolayer MoS₂ allows strong optical second harmonic generation. The second harmonic of an 810-nm pulse is generated in a mechanically exfoliated monolayer, with a nonlinear susceptibility on the order of 10⁻⁷ m/V. The susceptibility reduces by a factor...

[Phys. Rev. B 87, 161403] Published Mon Apr 15, 2013

Gated terahertz cyclotron resonance measurements on epitaxial Bi₂Se₃ thin films capped with In₂Se₃ enable the first spectroscopic characterization of a single topological interface state from the vicinity of the Dirac point to above the conduction band edge. A precipitous drop in the scattering rate...

[Phys. Rev. B 87, 155126] Published Mon Apr 15, 2013

We propose and analyze a mesoscopic device producing on-demand entangled pairs of electrons. The system consists of two capacitively coupled Mach-Zehnder interferometers implemented in a quantum Hall structure. A pair of electron wave packets is injected into the chiral edge states of two (of the fo...

[Phys. Rev. B 87, 165302] Published Fri Apr 12, 2013

The influence of defects on the local structural, electronic, and chemical properties of a surface oxide on Cu(100) were investigated using atomic resolution three-dimensional force mapping combined with tunneling current measurements and ab initio density functional theory. Results reveal that the ...

[Phys. Rev. B 87, 155414] Published Fri Apr 12, 2013

We present a theory of the spin Hall magnetoresistance (SMR) in multilayers made from an insulating ferromagnet F, such as yttrium iron garnet (YIG), and a normal metal N with spin-orbit interactions, such as platinum (Pt). The SMR is induced by the simultaneous action of spin Hall and inverse spin ...

[Phys. Rev. B 87, 144411] Published Fri Apr 12, 2013

We introduce and study a class of anyon models that are a natural generalization of Ising anyons and Majorana fermion zero modes. These models combine an Ising anyon sector with a sector associated with SO(m)₂ Chern-Simons theory. We show how they can arise in a simple scenario for electron fraction...

[Phys. Rev. B 87, 165421] Published Thu Apr 11, 2013

Noise measurements are a probe beyond simple electronic transport that can reveal additional information about electronic correlations and inelastic processes. Here we report noise measurements in individual electromigrated nanojunctions, examining the evolution from the many-channel regime to the t...

[Phys. Rev. B 87, 155411] Published Thu Apr 11, 2013