A chiral spin liquid is predicted to be realizable in a simple time-reversal-invariant Kondo-Heisenberg model.

[Phys. Rev. Lett. 119, 247203] Published Fri Dec 15, 2017

]]>We show how to realize two-component fractional quantum Hall phases in monolayer graphene by optically driving the system. A laser is tuned into resonance between two Landau levels, giving rise to an effective tunneling between these two synthetic layers. Remarkably, because of this coupling, the in...

[Phys. Rev. Lett. 119, 247403] Published Fri Dec 15, 2017

]]>We study the dynamics of excitonic insulators coupled to phonons using the time-dependent mean-field theory. Without phonon couplings, the linear response is given by the damped amplitude oscillations of the order parameter with a frequency equal to the minimum band gap. A phonon coupling to the int...

[Phys. Rev. Lett. 119, 247601] Published Fri Dec 15, 2017

]]>We present a theoretical analysis of two-dimensional Dirac-Rashba systems in the presence of disorder and external perturbations. We unveil a set of exact symmetry relations (Ward identities) that impose strong constraints on the spin dynamics of Dirac fermions subject to proximity-induced interacti...

[Phys. Rev. Lett. 119, 246801] Published Thu Dec 14, 2017

]]>The many body localization (MBL) of spin-$\frac{1}{2}$ fermions poses a challenging problem. It is known that the disorder in the charge sector may be insufficient to cause full MBL. Here, we study dynamics of a single hole in one dimensional $t\text{\u2212}J$ model subject to a random magnetic field. We show that strong di...

[Phys. Rev. Lett. 119, 246601] Published Wed Dec 13, 2017

]]>Thin films of amorphous indium oxide undergo a magnetic field driven superconducting to insulator quantum phase transition. In the insulating phase, the current-voltage characteristics show large current discontinuities due to overheating of electrons. We show that the onset voltage for the disconti...

[Phys. Rev. Lett. 119, 247001] Published Wed Dec 13, 2017

]]>We study the topological properties of magnon excitations in three-dimensional antiferromagnets, where the ground state configuration is invariant under time reversal followed by space inversion ($PT$ symmetry). We prove that Dirac points and nodal lines, the former being the limiting case of the latt...

[Phys. Rev. Lett. 119, 247202] Published Wed Dec 13, 2017

]]>We report a systematic plasmonic study of twisted bilayer graphene (TBLG)—two graphene layers stacked with a twist angle. Through real-space nanoimaging of TBLG single crystals with a wide distribution of twist angles, we find that TBLG supports confined infrared plasmons that are sensitively depend...

[Phys. Rev. Lett. 119, 247402] Published Wed Dec 13, 2017

]]>Theorists have discovered topological insulators that are insulating in their interior and on their surfaces but have conducting channels at corners or along edges.

[Phys. Rev. Lett. 119, 246401] Published Mon Dec 11, 2017

]]>Theorists have discovered topological insulators that are insulating in their interior and on their surfaces but have conducting channels at corners or along edges.

[Phys. Rev. Lett. 119, 246402] Published Mon Dec 11, 2017

]]>We study a class of continuous spin models with bond disorder including the kagome Heisenberg antiferromagnet. For weak disorder strength, we find discrete ground states whose number grows exponentially with system size. These states do not exhibit zero-energy excitations characteristic of highly fr...

[Phys. Rev. Lett. 119, 247201] Published Mon Dec 11, 2017

]]>The generation and recombination dynamics of multiple excitons in nanocrystals (NCs) have attracted much attention from the viewpoints of fundamental physics and device applications. However, the quantum coherence of multiple exciton states in NCs still remains unclear due to a lack of experimental ...

[Phys. Rev. Lett. 119, 247401] Published Mon Dec 11, 2017

]]>We present a method for computing the full probability distribution function of quadratic observables such as particle number or magnetization for the Fermi-Hubbard model within the framework of determinantal quantum Monte Carlo calculations. Especially in cold atom experiments with single-site reso...

[Phys. Rev. Lett. 119, 236401] Published Wed Dec 06, 2017

]]>The insulating honeycomb magnet $\alpha \text{\u2212}{\mathrm{RuCl}}_{3}$ exhibits fractionalized excitations that signal its proximity to a Kitaev quantum spin liquid state; however, at $T=0$, fragile long-range magnetic order arises from non-Kitaev terms in the Hamiltonian. Spin vacancies in the form of ${\mathrm{Ir}}^{3+}$ substituted for Ru are f...

[Phys. Rev. Lett. 119, 237203] Published Wed Dec 06, 2017

]]>We experimentally study magnetic resonances in the helical and conical magnetic phases of the chiral magnetic insulator ${\mathrm{Cu}}_{2}{\mathrm{OSeO}}_{3}$ at the temperature $T=5\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{K}$. Using a broadband microwave spectroscopy technique based on vector network analysis, we identify three distinct sets of helimagnon resonances in...

[Phys. Rev. Lett. 119, 237204] Published Wed Dec 06, 2017

]]>Dynamical mean-field theory (DMFT) studies frequently observe a fine structure in the local spectral function of the SU(2) Fermi-Hubbard model at half filling: In the metallic phase close to the Mott transition, subpeaks emerge at the inner edges of the Hubbard bands. Here we demonstrate that these ...

[Phys. Rev. Lett. 119, 236402] Published Tue Dec 05, 2017

]]>For the endohedral fullerene molecule ${\mathrm{HoLu}}_{2}\mathrm{N}@{\mathrm{C}}_{80}$, it is shown that the endohedral ${\mathrm{HoLu}}_{2}\mathrm{N}$ unit may be oriented in a magnetic field. The Ho magnetic moment is fixed in the strong ligand field and aligns along the holmium-nitrogen axis. The torque of a magnetic field on the Ho magnetic moment leads to ...

[Phys. Rev. Lett. 119, 237202] Published Tue Dec 05, 2017

]]>Experiments on a copper-based high-temperature superconductor uncover the existence of vortex states—a hallmark of conventional superconductivity.

[Phys. Rev. Lett. 119, 237001] Published Mon Dec 04, 2017

]]>We measure the gate voltage (${V}_{g}$) dependence of the superconducting properties and the spin-orbit interaction in the (111)-oriented ${\mathrm{LaAlO}}_{3}/\mathrm{SrTi}{\mathrm{O}}_{3}$ interface. Superconductivity is observed in a dome-shaped region in the carrier density-temperature phase diagram with the maxima of superconducting transi...

[Phys. Rev. Lett. 119, 237002] Published Mon Dec 04, 2017

]]>The formation of the triangular Skyrmion lattice is found in a tetragonal polar magnet ${\mathrm{VOSe}}_{2}{\mathrm{O}}_{5}$. By magnetization and small-angle neutron scattering measurements on the single crystals, we identify a cycloidal spin state at zero field and a Néel-type Skyrmion-lattice phase under a magnetic field alon...

[Phys. Rev. Lett. 119, 237201] Published Mon Dec 04, 2017

]]>$\alpha \text{\u2212}{\mathrm{RuCl}}_{3}$ is a leading candidate material for the observation of physics related to the Kitaev quantum spin liquid (QSL). By combined susceptibility, specific-heat, and nuclear-magnetic-resonance measurements, we demonstrate that $\alpha \text{\u2212}{\mathrm{RuCl}}_{3}$ undergoes a quantum phase transition to a QSL in a magnetic fiel...

[Phys. Rev. Lett. 119, 227208] Published Fri Dec 01, 2017

]]>The symmetric splitting of two spin-wave branches in an antiferromagnetic resonance (AFR) experiment has been an essential measurement of antiferromagnets for over half a century. In this work, circularly polarized time-domain THz spectroscopy experiments performed on the low symmetry multiferroic h...

[Phys. Rev. Lett. 119, 227601] Published Fri Dec 01, 2017

]]>A method is proposed for measuring the classical Hall viscosity of a two-dimensional electron gas under a magnetic field, via signatures of hydrodynamic transport.

[Phys. Rev. Lett. 119, 226602] Published Thu Nov 30, 2017

]]>Topological phases derived from point degeneracies in photonic band structures show intriguing and unique behavior. Previously identified band degeneracies are based on accidental degeneracies and subject to engineering on a case-by-case basis. Here we show that deterministic pseudo Weyl points with...

[Phys. Rev. Lett. 119, 227401] Published Thu Nov 30, 2017

]]>Experiments show that a semiconducting quantum dot containing nearly 100 electrons can operate as an effective spin 1/2 qubit.

[Phys. Rev. Lett. 119, 227701] Published Thu Nov 30, 2017

]]>We study the electronic transport across an electrostatically gated lateral junction in a HgTe quantum well, a canonical 2D topological insulator, with and without an applied magnetic field. We control the carrier density inside and outside a junction region independently and hence tune the number a...

[Phys. Rev. Lett. 119, 226401] Published Wed Nov 29, 2017

]]>We have measured excess carrier lifetime in silicon using photoexcited muon spin spectroscopy. Positive muons implanted deep in a wafer can interact with the optically injected excess carriers and directly probe the bulk carrier lifetime while minimizing the effect from surface recombination. The me...

[Phys. Rev. Lett. 119, 226601] Published Wed Nov 29, 2017

]]>Experimental evidence is presented for the realization of a 2D Dirac semimetal in black phosphorous, a material in which, unlike graphene, the Dirac point remains stable despite spin-orbit coupling.

[Phys. Rev. Lett. 119, 226801] Published Wed Nov 29, 2017

]]>We present the first observation of dynamically modulated quantum phase transition between two distinct charge density wave (CDW) phases in two-dimensional $2H\text{\u2212}{\mathrm{NbSe}}_{2}$. There is recent spectroscopic evidence for the presence of these two quantum phases, but its evidence in bulk measurements remained el...

[Phys. Rev. Lett. 119, 226802] Published Wed Nov 29, 2017

]]>The pseudogap metal phase of the hole-doped cuprate superconductors has two seemingly unrelated characteristics: a gap in the electronic spectrum in the “antinodal” region of the square lattice Brillouin zone and discrete broken symmetries. We present a SU(2) gauge theory of quantum fluctuations of ...

[Phys. Rev. Lett. 119, 227002] Published Wed Nov 29, 2017

]]>Precession and relaxation predominantly characterize the real-time dynamics of a spin driven by a magnetic field and coupled to a large Fermi sea of conduction electrons. We demonstrate an anomalous precession with frequency higher than the Larmor frequency or with inverted orientation in the limit ...

[Phys. Rev. Lett. 119, 227203] Published Wed Nov 29, 2017

]]>Quantum spin ice, modeled for magnetic rare-earth pyrochlores, has attracted great interest for hosting a U(1) quantum spin liquid, which involves spin-ice monopoles as gapped deconfined spinons, as well as gapless excitations analogous to photons. However, the global phase diagram under a [111] mag...

[Phys. Rev. Lett. 119, 227204] Published Wed Nov 29, 2017

]]>We identify and investigate thermal spin transport phenomena in sputter-deposited $\mathrm{Pt}/{\mathrm{NiFe}}_{2}{\mathrm{O}}_{x}$ ($4\ge x\ge 0$) bilayers. We separate the voltage generated by the spin Seebeck effect from the anomalous Nernst effect (ANE) contributions and even disentangle the ANE in the ferromagnet (FM) from the ANE produced ...

[Phys. Rev. Lett. 119, 227205] Published Wed Nov 29, 2017

]]>Quantum spin networks having engineered geometries and interactions are eagerly pursued for quantum simulation and access to emergent quantum phenomena such as spin liquids. Spin-$1/2$ centers are particularly desirable, because they readily manifest coherent quantum fluctuations. Here we introduce a ...

[Phys. Rev. Lett. 119, 227206] Published Wed Nov 29, 2017

]]>The prototypical magnetic memory shape alloy ${\mathrm{Ni}}_{2}\mathrm{MnGa}$ undergoes various phase transitions as a function of the temperature, pressure, and doping. In the low-temperature phases below 260 K, an incommensurate structural modulation occurs along the [110] direction which is thought to arise from the soft...

[Phys. Rev. Lett. 119, 227207] Published Wed Nov 29, 2017

]]>A rapid and anisotropic modification of the Fermi-surface shape can be associated with abrupt changes in crystalline lattice geometry or in the magnetic state of a material. We show that such an electronic topological transition is at the basis of the formation of an unusual pressure-induced tetrago...

[Phys. Rev. Lett. 119, 227003] Published Tue Nov 28, 2017

]]>We report measurements of optical absorption in the zigzag antiferromagnet $\alpha \text{\u2212}{\mathrm{RuCl}}_{3}$ as a function of temperature $T$, magnetic field $B$, and photon energy $\hslash \omega $ in the range $\sim 0.3$–8.3 meV, using time-domain terahertz spectroscopy. Polarized measurements show that threefold rotational symmetry is broken in t...

[Phys. Rev. Lett. 119, 227201] Published Tue Nov 28, 2017

]]>We report on terahertz spectroscopy of quantum spin dynamics in $\alpha \text{\u2212}{\mathrm{RuCl}}_{3}$, a system proximate to the Kitaev honeycomb model, as a function of temperature and magnetic field. We follow the evolution of an extended magnetic continuum below the structural phase transition at ${T}_{s2}=62\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{K}$. With the onset of ...

[Phys. Rev. Lett. 119, 227202] Published Tue Nov 28, 2017

]]>A current of electrons with aligned spins can be used to modify magnetic order and superconductivity in an iron-based superconductor.

[Phys. Rev. Lett. 119, 227001] Published Mon Nov 27, 2017

]]>Researchers characterize the spin couplings in the prototypical single-molecule magnet Mn${}_{12}$ using an advanced neutron scattering technique.

[Phys. Rev. Lett. 119, 217202] Published Wed Nov 22, 2017

]]>We present the appearance of negative differential resistance (NDR) in spin-dependent electron transport through a few-atom spin chain. A chain of three antiferromagnetically coupled Fe atoms (Fe trimer) was positioned on a ${\mathrm{Cu}}_{2}\mathrm{N}/\mathrm{Cu}(100)$ surface and contacted with the spin-polarized tip of a scanning...

[Phys. Rev. Lett. 119, 217201] Published Tue Nov 21, 2017

]]>The emission rate of a point dipole can be strongly increased in the presence of a well-designed optical antenna. Yet, optical antenna design is largely based on radio-frequency rules, ignoring, e.g., Ohmic losses and non-negligible field penetration in metals at optical frequencies. Here, we combin...

[Phys. Rev. Lett. 119, 217401] Published Tue Nov 21, 2017

]]>Prominent systems like the high-${T}_{c}$ cuprates and heavy fermions display intriguing features going beyond the quasiparticle description. The Sachdev-Ye-Kitaev (SYK) model describes a $(0+1)\mathrm{D}$ quantum cluster with random all-to-all *four*-fermion interactions among $N$ fermion modes which becomes exactly sol...

[Phys. Rev. Lett. 119, 216601] Published Mon Nov 20, 2017

]]>The experimental observation of band hybridization in a cuprate superconductor explains why the highest superconducting transition temperatures occur in samples with only three coupled copper dioxide layers.

[Phys. Rev. Lett. 119, 217001] Published Mon Nov 20, 2017

]]>We investigate the magnetic phase diagram near the upper critical field of ${\mathrm{KFe}}_{2}{\mathrm{As}}_{2}$ by magnetic torque and specific heat experiments using a high-resolution piezorotary positioner to precisely control the parallel alignment of the magnetic field with respect to the FeAs layers. We observe a clear dou...

[Phys. Rev. Lett. 119, 217002] Published Mon Nov 20, 2017

]]>Parafermionic zero modes are a novel set of excitations displaying non-Abelian statistics somewhat richer than that of Majorana modes. These modes are predicted to occur when nearby fractional quantum Hall edge states are gapped by an interposed superconductor. Despite substantial experimental progr...

[Phys. Rev. Lett. 119, 217701] Published Mon Nov 20, 2017

]]>The theoretical proposal of chiral fermions in topological semimetals has led to a significant effort towards their experimental realization. In particular, the Fermi surfaces of chiral semimetals carry quantized Chern numbers, making them an attractive platform for the observation of exotic transpo...

[Phys. Rev. Lett. 119, 206401] Published Fri Nov 17, 2017

]]>Exotic massless fermionic excitations with nonzero Berry flux, other than the Dirac and Weyl fermions, could exist in condensed matter systems under the protection of crystalline symmetries, such as spin-1 excitations with threefold degeneracy and spin-$3/2$ Rarita-Schwinger-Weyl fermions. Herein, by ...

[Phys. Rev. Lett. 119, 206402] Published Fri Nov 17, 2017

]]>A low temperature superconducting phase (3-4K) in ferroelectric SnP is experimentally observed when its ferroelectric phase is suppressed through hydrostatic pressure.

[Phys. Rev. Lett. 119, 207001] Published Fri Nov 17, 2017

]]>A theoretical proposal suggests that a ferromagnet could be optically switched into an antiferromagnet by manipulating the double exchange interaction.

[Phys. Rev. Lett. 119, 207202] Published Thu Nov 16, 2017

]]>We reveal that concurrent events of inherent entropy boosting and increased synchronization between $A$- and $B$-site cation vibrations of an $AB{\mathrm{O}}_{3}$-type perovskite structure give rise to a larger piezoelectric response in a ferroelectric system at its morphotropic phase boundary (MPB). It is further evid...

[Phys. Rev. Lett. 119, 207604] Published Thu Nov 16, 2017

]]>Capillary and van der Waals forces cause nanotubes to deform or even collapse under metal contacts. Using *ab initio* band structure calculations, we find that these deformations reduce the band gap by as much as 30%, while fully collapsed nanotubes become metallic. Moreover, degeneracy lifting due to...

[Phys. Rev. Lett. 119, 207701] Published Thu Nov 16, 2017

]]>Many aspects of many-body localization (MBL) transitions remain elusive so far. Here, we propose a higher-dimensional generalization of the Sachdev-Ye-Kitaev (SYK) model and show that it exhibits a MBL transition. The model on a bipartite lattice has $N$ Majorana fermions with SYK interactions on each...

[Phys. Rev. Lett. 119, 206602] Published Wed Nov 15, 2017

]]>The Sachdev-Ye-Kitaev (SYK) model is a concrete solvable model to study non-Fermi liquid properties, holographic duality, and maximally chaotic behavior. In this work, we consider a generalization of the SYK model that contains two SYK models with a different number of Majorana modes coupled by quad...

[Phys. Rev. Lett. 119, 207603] Published Wed Nov 15, 2017

]]>We report on fundamental aspects of spin dynamics in heterostructures of graphene and transition metal dichalcogenides (TMDCs). By using realistic models derived from first principles we compute the spin lifetime anisotropy, defined as the ratio of lifetimes for spins pointing out of the graphene pl...

[Phys. Rev. Lett. 119, 206601] Published Tue Nov 14, 2017

]]>We study topological defects in anisotropic ferromagnets with competing interactions near the Lifshitz point. We show that Skyrmions and bimerons are stable in a large part of the phase diagram. We calculate Skyrmion-Skyrmion and meron-meron interactions and show that Skyrmions attract each other an...

[Phys. Rev. Lett. 119, 207201] Published Tue Nov 14, 2017

]]>The negative longitudinal piezoelectric effect is predicted to be a general phenomenon caused by the strong ionic bonds, whose origin lies in small effective charges and rigid potential energy surfaces.

[Phys. Rev. Lett. 119, 207601] Published Tue Nov 14, 2017

]]>Recently, a plastic crystal of quinuclidinium perrhenate (${\mathrm{HQReO}}_{4}$) was reported to have the feasibility of controlling the crystallographic orientation in the grown crystal, but the corresponding temperature window is only about 22 K (345–367 K). Such a narrow window and uncertain ferroelectricity at...

[Phys. Rev. Lett. 119, 207602] Published Tue Nov 14, 2017

]]>A vortex-like magnetic spin structure inside a small disk of material is stable without an external magnetic field and might be useful for information storage or processing.

[Phys. Rev. Lett. 119, 197205] Published Fri Nov 10, 2017

]]>We show that Be exhibits amphoteric behavior in GaN, involving switching between substitutional and interstitial positions in the lattice. This behavior is observed through the dominance of ${\mathrm{Be}}_{\mathrm{Ga}}$ in the positron annihilation signals in Be-doped GaN, while the emergence of ${V}_{\mathrm{Ga}}$ at high temperatures is ...

[Phys. Rev. Lett. 119, 196404] Published Thu Nov 09, 2017

]]>Experimental evidence is presented for the spin polarization of Yu-Shiba-Rusinov states induced by the presence of a single magnetic atom on a superconductor.

[Phys. Rev. Lett. 119, 197002] Published Thu Nov 09, 2017

]]>The first Weyl semimetal was recently discovered in the NbP class of compounds. Although the topology of these novel materials has been identified, the surface properties are not yet fully understood. By means of scanning tunneling spectroscopy, we find that NbP’s (001) surface hosts a pair of Dirac...

[Phys. Rev. Lett. 119, 196403] Published Wed Nov 08, 2017

]]>Combining ultrahigh sensitivity, spatial resolution, and the capability to resolve chemical information, tip-enhanced Raman spectroscopy (TERS) is a powerful tool to study molecules or nanoscale objects. Here we show that TERS can also be a powerful tool in studying two-dimensional materials. We hav...

[Phys. Rev. Lett. 119, 196803] Published Wed Nov 08, 2017

]]>Using a variational Monte Carlo method, we study the competition of strong electron-electron and electron-phonon interactions in the ground state of the Holstein-Hubbard model on a square lattice. At half filling, an extended intermediate metallic or weakly superconducting (SC) phase emerges, sandwi...

[Phys. Rev. Lett. 119, 197001] Published Wed Nov 08, 2017

]]>Modulation and $\delta $-doping strategies, in which atomically thin layers of charged dopants are precisely deposited within a heterostructure, have played enabling roles in the discovery of new physical behavior in electronic materials. Here, we demonstrate a purely structural “$\delta $-doping” strategy in compl...

[Phys. Rev. Lett. 119, 197204] Published Wed Nov 08, 2017

]]>It has been argued that the 0.7 anomaly in quantum point contacts (QPCs) is due to an enhanced density of states at the top of the QPC barrier (the van Hove ridge), which strongly enhances the effects of interactions. Here, we analyze their effect on dynamical quantities. We find that they pin the v...

[Phys. Rev. Lett. 119, 196401] Published Tue Nov 07, 2017

]]>We carried out temperature-dependent (20–550 K) measurements of resonant inelastic x-ray scattering on ${\mathrm{LaCoO}}_{3}$ to investigate the evolution of its electronic structure across the spin-state crossover. In combination with charge-transfer multiplet calculations, we accurately quantified the renomalized...

[Phys. Rev. Lett. 119, 196402] Published Tue Nov 07, 2017

]]>When graphene is placed on a monolayer of semiconducting transition metal dichalcogenide (TMD) its band structure develops rich spin textures due to proximity spin-orbital effects with interfacial breaking of inversion symmetry. In this work, we show that the characteristic spin winding of low-energ...

[Phys. Rev. Lett. 119, 196801] Published Tue Nov 07, 2017

]]>We propose a protocol for the measurement of adiabatic phases of periodically driven quantum systems coupled to an open cavity that enables dispersive readout. It turns out that the cavity transmission exhibits peaks at frequencies determined by a resonance condition that involves the dynamical and ...

[Phys. Rev. Lett. 119, 196802] Published Tue Nov 07, 2017

]]>We consider a model of Dirac fermions in $2+1$ dimensions with dynamically generated, anticommuting SO(3) Néel and ${Z}_{2}$ Kekulé mass terms that permits sign-free quantum Monte Carlo simulations. The phase diagram is obtained from finite-size scaling and includes a direct and continuous transition between...

[Phys. Rev. Lett. 119, 197203] Published Tue Nov 07, 2017

]]>A combination of novel technological and fundamental physics prospects has sparked a huge interest in pure spin transport in magnets, starting with ferromagnets and spreading to antiferro- and ferrimagnets. We present a theoretical study of spin transport across a ferrimagnet–nonmagnetic conductor i...

[Phys. Rev. Lett. 119, 197201] Published Mon Nov 06, 2017

]]>A class of magnetic materials can be reordered at the nanoscale more rapidly than the type usually found in magnetic hard drives, offering a possible route to faster memory devices.

[Phys. Rev. Lett. 119, 197202] Published Mon Nov 06, 2017

]]>We show that the evolution of two-component particles governed by a two-dimensional spin-orbit lattice Hamiltonian can reveal transitions between topological phases. A kink in the mean width of the particle distribution signals the closing of the band gap, a prerequisite for a quantum phase transiti...

[Phys. Rev. Lett. 119, 197401] Published Mon Nov 06, 2017

]]>We study the phase transition between a trivial and a time-reversal-invariant topological superconductor in a single-band system. By analyzing the interplay of symmetry, topology, and energetics, we show that for a generic normal state band structure, the phase transition occurs via extended interme...

[Phys. Rev. Lett. 119, 187003] Published Fri Nov 03, 2017

]]>We show that, in optical pump-probe experiments on bulk samples, the statistical distribution of the intensity of ultrashort light pulses after interaction with a nonequilibrium complex material can be used to measure the time-dependent noise of the current in the system. We illustrate the general a...

[Phys. Rev. Lett. 119, 187403] Published Fri Nov 03, 2017

]]>Junctions created by coupling two superconductors via a semiconductor nanowire in the presence of high magnetic fields are the basis for the potential detection, fusion, and braiding of Majorana bound states. We study $\mathrm{NbTiN}/\mathrm{InSb}$ $\text{nanowire}/\mathrm{NbTiN}$ Josephson junctions and find that the dependence of the ...

[Phys. Rev. Lett. 119, 187704] Published Fri Nov 03, 2017

]]>We show how the interference between superfluid spin currents can endow spin circuits with coherent logic functionality. While the hydrodynamic aspects of the linear-response collective spin transport obviate interference features, we focus on the nonlinear regime, where the critical supercurrent is...

[Phys. Rev. Lett. 119, 187705] Published Fri Nov 03, 2017

]]>We observed broken-symmetry quantum Hall effects and level crossings between spin- and valley- resolved Landau levels (LLs) in Bernal stacked trilayer graphene. When the magnetic field was tilted with respect to the sample normal from 0° to 66°, the LL crossings formed at intersections of zeroth and...

[Phys. Rev. Lett. 119, 186802] Published Thu Nov 02, 2017

]]>The lattice response of a prototype Mott insulator, ${\mathrm{SmTiO}}_{3}$, to hole doping is investigated with atomic-scale spatial resolution. ${\mathrm{SmTiO}}_{3}$ films are doped with Sr on the Sm site with concentrations that span the insulating and metallic sides of the filling-controlled Mott metal-insulator transition (MI...

[Phys. Rev. Lett. 119, 186803] Published Thu Nov 02, 2017

]]>Quantum Hall states can be characterized by their chiral edge modes. Upon softening the edge potential, the edge has long been known to undergo spontaneous reconstruction driven by charging effects. In this Letter we demonstrate a qualitatively distinct phenomenon driven by exchange effects, in whic...

[Phys. Rev. Lett. 119, 186804] Published Thu Nov 02, 2017

]]>The magnetic properties of the pyrochlore iridate material ${\mathrm{Eu}}_{2}{\mathrm{Ir}}_{2}{\mathrm{O}}_{7}$ ($5{d}^{5}$) have been studied based on first principles calculations, where the crystal field splitting $\mathrm{\Delta}$, spin-orbit coupling (SOC) $\lambda $, and Coulomb interaction $U$ within Ir $5d$ orbitals all play significant roles. The ground state phase dia...

[Phys. Rev. Lett. 119, 187203] Published Thu Nov 02, 2017

]]>Noncollinear antiferromagnets, such as ${\mathrm{Mn}}_{3}\mathrm{Sn}$ and ${\mathrm{Mn}}_{3}\mathrm{Ir}$, were recently shown to be analogous to ferromagnets in that they have a large anomalous Hall effect. Here we show that these materials are similar to ferromagnets in another aspect: the charge current in these materials is spin polarized. In ad...

[Phys. Rev. Lett. 119, 187204] Published Thu Nov 02, 2017

]]>Grover’s algorithm, which finds an element in an unsorted list, has been implemented using a nuclear spin in a single-molecule magnet.

[Phys. Rev. Lett. 119, 187702] Published Thu Nov 02, 2017

]]>Unconventional superconductivity in many materials is believed to be mediated by magnetic fluctuations. It is an open question how magnetic order can emerge from a superconducting condensate and how it competes with the magnetic spin resonance in unconventional superconductors. Here we study a model...

[Phys. Rev. Lett. 119, 187002] Published Wed Nov 01, 2017

]]>ZrSiS exhibits a frequency-independent interband conductivity $\sigma (\omega )=\text{const}(\omega )\equiv {\sigma}_{\mathrm{flat}}$ in a broad range from 250 to $2500\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\mathrm{cm}}^{-1}$ (30–300 meV). This makes ZrSiS similar to (quasi-)two-dimensional Dirac electron systems, such as graphite and graphene. We assign the flat optical conductivity to the transition...

[Phys. Rev. Lett. 119, 187401] Published Wed Nov 01, 2017

]]>Excitons dominate the optical properties of monolayer transition metal dichalcogenides (TMDs). Besides optically accessible bright exciton states, TMDs exhibit also a multitude of optically forbidden dark excitons. Here, we show that efficient exciton-phonon scattering couples bright and dark states...

[Phys. Rev. Lett. 119, 187402] Published Wed Nov 01, 2017

]]>We study micromotion in two-dimensional periodically driven systems in which all bulk Floquet eigenstates are localized by disorder. We show that this micromotion gives rise to a quantized time-averaged orbital magnetization density in any region completely filled with fermions. The quantization of ...

[Phys. Rev. Lett. 119, 186801] Published Tue Oct 31, 2017

]]>A one-dimensional time-reversal-invariant topological superconductor hosts a Majorana Kramers pair at each end, where time-reversal symmetry acts as a supersymmetry that flips local fermion parity. We examine the transport anomaly of such a superconductor, floating and tunnel-coupled to normal leads...

[Phys. Rev. Lett. 119, 187701] Published Tue Oct 31, 2017

]]>We investigated the effect of an in-plane electric field on drifting spins in a GaAs quantum well. Kerr rotation images of the drifting spins revealed that the spin precession wavelength increases with increasing drift velocity regardless of the transport direction. A model developed for drifting sp...

[Phys. Rev. Lett. 119, 187703] Published Tue Oct 31, 2017

]]>We report on temperature-dependent pair distribution function measurements of ${\mathrm{Sr}}_{1-x}{\mathrm{Na}}_{x}{\mathrm{Fe}}_{2}{\mathrm{As}}_{2}$, an iron-based superconductor system that contains a magnetic phase with reentrant tetragonal symmetry, known as the magnetic ${C}_{4}$ phase. Quantitative refinements indicate that the instantaneous local structur...

[Phys. Rev. Lett. 119, 187001] Published Mon Oct 30, 2017

]]>We report neutron scattering measurements on ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$, a new addition to the $XY$ family of frustrated pyrochlore magnets. Symmetry analysis of our elastic scattering data shows that ${\mathrm{Er}}_{2}{\mathrm{Pt}}_{2}{\mathrm{O}}_{7}$ orders into the $k=0$, ${\mathrm{\Gamma}}_{7}$ magnetic structure (the Palmer-Chalker state), at ${T}_{N}=0.38\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{K}$. This contrasts with its ...

[Phys. Rev. Lett. 119, 187201] Published Mon Oct 30, 2017

]]>${\mathrm{Er}}_{2}{\mathrm{Sn}}_{2}{\mathrm{O}}_{7}$ remains a puzzling case among the extensively studied frustrated compounds of the rare-earth pyrochlore family. Indeed, while a first-order transition towards a long-range antiferromagnetic state with the so-called Palmer-Chalker structure is theoretically predicted, it has not yet been obs...

[Phys. Rev. Lett. 119, 187202] Published Mon Oct 30, 2017

]]>Different interatomic spin interactions in graphene-regulated Mn atomic clusters are investigated by low-temperature scanning tunneling microscopy and magnetic-field-dependent inelastic spin excitation spectroscopy. All dimers observed exhibit an antiferromagnetic (AFM) singlet ground state and spin...

[Phys. Rev. Lett. 119, 176806] Published Fri Oct 27, 2017

]]>Spin orbit interactions in GaAs quantum wells are switched on and off by tuning the spin-flip tunneling rate.

[Phys. Rev. Lett. 119, 176807] Published Fri Oct 27, 2017

]]>We present a perturbation approach rooted in time-dependent density-functional theory to calculate electron-hole ($e\text{\u2212}h$) pair excitation spectra during the nonadiabatic vibrational damping of adsorbates on metal surfaces. Our analysis for the benchmark systems CO on Cu(100) and Pt(111) elucidates the ...

[Phys. Rev. Lett. 119, 176808] Published Fri Oct 27, 2017

]]>A topological variant of the Hall effect that relies on spin chirality is observed in a topological insulator at four quantum layers, but vanishes for fewer and more layers.

[Phys. Rev. Lett. 119, 176809] Published Fri Oct 27, 2017

]]>With reduced dimensionality, it is often easier to modify the properties of ultrathin films than their bulk counterparts. Strain engineering, usually achieved by choosing appropriate substrates, has been proven effective in controlling the properties of perovskite oxide films. An emerging alternativ...

[Phys. Rev. Lett. 119, 177203] Published Fri Oct 27, 2017

]]>We investigate zero-bias conductance peaks that arise from coalescing subgap Andreev states, consistent with emerging Majorana zero modes, in hybrid semiconductor-superconductor wires defined in a two-dimensional $\mathrm{InAs}/\mathrm{Al}$ heterostructure using top-down lithography and gating. The measurements indicat...

[Phys. Rev. Lett. 119, 176805] Published Thu Oct 26, 2017

]]>An applied electric field can be used to control a twisted form of magnetic ordering inside small domains of multiferroic materials.

[Phys. Rev. Lett. 119, 177201] Published Thu Oct 26, 2017

]]>Recent intense effort has been devoted to exploring different manifestations of resonant excitations of strongly coupled plasmons and excitons, but so far such studies have been limited to situations where the Fano- or Rabi-type spectra are largely symmetric at zero detuning. Using a newly developed...

[Phys. Rev. Lett. 119, 177401] Published Thu Oct 26, 2017

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