Latest in cond-mat.supr-con

total 31079took 0.18s
Extended magnetic dome induced by low pressures in superconducting FeSe$_\mathrm{1\text{-}x}$S$_\mathrm{x}$May 17 2019We report muon spin rotation ($\mu$SR) and magnetization measurements under pressure on Fe$_{1+\delta}$Se$_\mathrm{1\text{-}x}$S$_\mathrm{x}$ with x $\approx 0.11$. We find an extended dome of long range magnetic order above $p\approx0.6$ GPa spanning ... More
Crystal growth and characterization of the antiperovskite superconductor MgC1-xNi3-yMay 16 2019By varying the parameters controlling the growth of crystals, including the thermodynamic variables, such as temperature, pressure, and reagent composition and the kinetic factors, namely reaction time and cooling rate, we found the most appropriate conditions ... More
Unveiling the vortex glass phase in the surface and volume of a type-II superconductorMay 16 2019Order-disorder transitions between glassy phases are quite common in nature and yet a comprehensive survey of the microscopic structural changes remains elusive since the scale of the constituents is tiny and in most cases few of them take part in the ... More
Coexistence of ferromagnetic fluctuations and superconductivity in the actinide superconductor UTe2May 16 2019We report low-temperature muon spin relaxation/rotation (muSR) measurements on single crystals of the actinide superconductor UTe2. Below 5 K we observe a continuous slowing down of magnetic fluctuations, which persists through the superconducting transition ... More
Functional Form of the Superconducting Critical Temperature from Machine LearningMay 16 2019Predicting the critical temperature $T_c$ of new superconductors is a notoriously difficult task, even for electron-phonon paired superconductors for which the theory is relatively well understood. Early attempts by McMillan and Allen and Dynes to improve ... More
A Perspective on Conventional High-Temperature Superconductors at High Pressure: Methods and MaterialsMay 16 2019Two hydrogen-rich materials: H$_3$S and LaH$_{10}$, synthesized at $megabar$ pressures have revolutionized the field of superconductivity by providing a first glimpse into the solution for the hundred-year-old problem of room-temperature superconductivity. ... More
Pressure-induced quantum critical point in a heavily hydrogen-doped iron-based superconductor LaFeAsOMay 16 2019An iron-based superconductor LaFeAsO$_{1-x}$H$_x$ (0 $\leq x \leq$ 0.6) undergoes two antiferromagnetic (AF) phases upon H doping. We investigated the second AF phase ($x$=0.6) using NMR techniques under pressure. At pressures up to 2 GPa, the ground ... More
Superconductivity in Uncollapsed Tetragonal LaFe2As2May 16 2019We report synthesis, crystal structure and superconductivity in ThCr2Si2-type LaFe2As2 (La122). La122 was synthesized at 960{\deg}C for 1.5 h under a pressure of 3.4 GPa. An as-synthesized La122 (non-superconductor) had a collapsed tetragonal structure ... More
Enhanced Superconductivity in Monolayer $T_d$-MoTe$_2$ with Tilted Ising Spin TextureMay 16 2019Crystalline two-dimensional (2D) superconductors with low carrier density are an exciting new class of materials in which superconductivity coexists with strong interactions, the effects of complex topology are not obscured by disorder, and electronic ... More
Optical control of the current-voltage relation in stacked superconductorsMay 15 2019We simulate the current-voltage relation of short layered superconductors, which we model as stacks of capacitively coupled Josephson junctions. The system is driven by external laser fields, in order to optically control the voltage drop across the junction. ... More
Pair spin-orbit interaction in low-dimensional electron systemsMay 15 2019The pair spin-orbit interaction (PSOI) is the spin-orbit component of the electron-electron interaction that originates from the Coulomb fields of the electrons. This relativistic component, which has been commonly assumed small in the low-energy approximation, ... More
Manipulating multi-vortex states in superconducting structuresMay 15 2019We demonstrate a method for manipulating small ensembles of vortices in multiply-connected superconducting structures. A micron-size magnetic particle attached to the tip of a silicon cantilever is used to locally apply magnetic flux through the superconducting ... More
Novel Fe-based superconductor LaFe2As2 in comparison with traditional pnictidesMay 15 2019The recently discovered Fe-based superconductor (FeBS) LaFe2As2 seems to break away from an established pattern that doping FeBS beyond 0.2e/Fe destroys superconductivity. LaFe2As2 has an apparent doping of 0.5e, yet superconducts at 12.1 K. Its Fermi ... More
Tuning the distance to a ferromagnetic quantum critical point in A2Cr3As3May 15 2019Although superconductivity in the vicinity of antiferromagnetic (AFM) instability has been extensively explored in the last three decades or so, superconductivity in compounds with a background of ferromagnetic (FM) spin fluctuations is still rare. We ... More
Universal behavior of the IMS domain formation in superconducting niobiumMay 15 2019In the intermediate mixed state (IMS) of type-II/1 superconductors, vortex lattice (VL) and Meissner state domains coexist due to a partially attractive vortex interaction. Using a neutron-based multiscale approach combined with magnetization measurements, ... More
$d$-wave superconducting gap observed in the protect-annealed electron-doped cuprate superconductors Pr$_{1.3-x}$La$_{0.7}$Ce$_{x}$CuO$_{4}$May 15 2019For electron-doped cuprates, the strong suppression of antiferromagnetic spin correlation by efficient reduction annealing by the "protect-annealing" method leads to superconductivity not only with lower Ce concentrations but also with higher transition ... More
Stability of Disordered Topological Superconducting Phases in Magnet--Superconductor Hybrid SystemsMay 15 2019Magnet-superconductor hybrid heterostructures constitute a promising candidate system for the quantum engineering of chiral topological superconductivity. Here, we investigate the stability of their topological phases in the presence of various types ... More
Electronic structure of Bi2Te3/FeTe heterostructure: implications for unconventional superconductivityMay 15 2019We have performed angle-resolved photoemission spectroscopy on a heterostructure consisting of topological insulator Bi2Te3 and iron chalcogenide FeTe fabricated on SrTiO3 substrate by molecular-beam-epitaxy technique. This system was recently found to ... More
Zero-Energy Modes on Superconducting Bismuth Islands Deposited on Fe(Te,Se)May 14 2019Topological superconductivity is one of the frontier research directions in condensed matter physics. One of the unique elementary excitations in topological superconducting state is the Majorana fermion (mode) which is its own antiparticle and obeys ... More
Protected superconductivity at the boundaries of charge-density-wave domainsMay 14 2019Solid $^4$He may acquire superfluid characteristics due to the frustration of the solid phase at grain boundaries. Here, we show that an analogous effect occurs in systems with competition among charge-density-waves (CDWs) and superconductivity in the ... More
Conductance-matrix symmetries of a three-terminal hybrid deviceMay 14 2019We present conductance-matrix measurements of a three-terminal superconductor-semiconductor hybrid device consisting of two normal leads and one superconducting lead. Using a symmetry decomposition of the conductance, we find that the antisymmetric components ... More
Hidden robust presence of a hole Fermi surface in a heavily electron doped iron based superconductor LaFe$_2$As$_2$May 14 2019We investigate the electronic structure of a recently discovered, heavily electron-doped iron based superconductor LaFe$_2$As$_2$. Although first principles calculation shows apparent absence of hole Fermi surfaces around the $\Gamma$ point, we reveal, ... More
Hidden robust presence of a hole Fermi surface in a heavily electron doped iron based superconductor LaFe$_2$As$_2$May 14 2019May 15 2019We investigate the electronic structure of a recently discovered, heavily electron-doped iron based superconductor LaFe$_2$As$_2$. Although first principles calculation shows apparent absence of hole Fermi surfaces around the $\Gamma$ point, we reveal, ... More
Nonlocal conductance spectroscopy of Andreev bound states: Symmetry relations and BCS chargesMay 14 2019Two-terminal conductance spectroscopy of superconducting devices is a common tool for probing Andreev and Majorana bound states. Here, we study theoretically a three-terminal setup, with two normal leads coupled to a grounded superconducting terminal. ... More
Fermi-Bose mixtures and BCS-BEC crossover in high-Tc superconductorsMay 14 2019In this review article we consider theoretically and give experimental support to the models of the Fermi-Bose mixtures and the BCS-BEC crossover compared with the strong-coupling approach, which can serve as the cornerstones on the way from high-temperature ... More
Fermi-Bose mixtures and BCS-BEC crossover in high-Tc superconductorsMay 14 2019May 15 2019In this review article we consider theoretically and give experimental support to the models of the Fermi-Bose mixtures and the BCS-BEC crossover compared with the strong-coupling approach, which can serve as the cornerstones on the way from high-temperature ... More
Slow Vortex Creep Induced by Strong Grain Boundary Pinning in Advanced Ba122 Superconducting TapesMay 14 2019We report the temperature, magnetic field and time dependences of magnetization in advanced Ba122 superconducting tapes. The sample exhibits a peculiar vortex creep behavior. Below 10 K, the normalized magnetization relaxation rate S=dln(-M)/dln(t) shows ... More
Transient trapping into metastable states in systems with competing ordersMay 14 2019The quench dynamics of a system involving two competing orders is investigated using a Ginzburg-Landau theory with relaxational dynamics. Modest differences in relaxation rates of the competing orders are found lead to post quench evolution into the local ... More
Direct visualization of local interaction forces in Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ vortex matterMay 14 2019We study the local vortex-vortex interaction force $\textbf{f}_i$ of the structure frozen during a field-cooling process in an electron-irradiated Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ sample. We compute this magnitude from snapshots of the vortex structure ... More
Anomalous doping evolution of nodal dispersion revealed by in-situ ARPES on continuously doped cupratesMay 13 2019We study the systematic doping evolution of nodal dispersions by in-situ angle-resolved photoemission spectroscopy on the continuously doped surface of a high-temperature superconductor Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$. We reveal that the nodal dispersion ... More
Phenomenological Description of the Spectral Function for the Pseudogap and Superconducting Phases of High-T$_c$ CupratesMay 13 2019We present a phenomenological Green's function to characterize the superconducting and pseudogap phases of the cuprates based on a microscopic theory of doped Mott insulators. In this framework, the "Fermi arc" and "kink" phenomena observed by angular-resolved ... More
Phenomenological Description of the Spectral Function for the Pseudogap and Superconducting Phases of High-T$_c$ CupratesMay 13 2019May 15 2019We present a phenomenological Green's function to characterize the superconducting and pseudogap phases of the cuprates based on a microscopic theory of doped Mott insulators. In this framework, the "Fermi arc" and "kink" phenomena observed by angle-resolved ... More
Knight Shift and Leading Superconducting Instability From Spin Fluctuations in Sr2RuO4May 12 2019Recent nuclear magnetic resonance studies [A. Pustogow {\it et al.}, arXiv:1904.00047] have challenged the prevalent chiral triplet pairing scenario proposed for Sr$_2$RuO$_4$. To provide guidance from microscopic theory as to which other pair states ... More
Nodeless superconductivity and preserved time-reversal symmetry in the noncentrosymmetric Mo3P superconductorMay 12 2019We report a comprehensive study of the noncentrosymmetric superconductor Mo$_3$P. Its bulk superconductivity, with $T_c = 5.5$ K, was characterized via electrical resistivity, magnetization, and heat-capacity measurements, while its microscopic electronic ... More
Multiple band-crossings and Fermi surface topology: role of double nonsymmorphic symmetries in MnP-type crystal structuresMay 12 2019We use relativistic ab-initio methods combined with model Hamiltonian approaches to analyze the normal-phase electronic and structural properties of the recently discovered WP superconductor. Remarkably, the outcomes of such study can be employed to set ... More
Higher-form symmetries and $d-wave$ superconductors from doped Mott insulatorsMay 12 2019One path to high-temperature cuprate superconductors is doping a Mott insulator. In this paper, we study this system from the view point of higher-form symmetries. On the introduction of slave bosons, the $t-J$ model at a finite hole doping can be written ... More
Superconductivity in Li-intercalated 1T-SnSe2 driven by electric-field gatingMay 11 2019Creating carrier reservoirs in layered compounds can effectively tune the carrier density, which often induces a variety of emergent properties. Based on solid-ion-conductor gating technique, we successfully induce superconductivity of 4.8 K in ultrathin ... More
Crystal structure of the unconventional spin-triplet superconductor UTe2 at low temperature by single crystal neutron diffractionMay 10 2019The crystal structure of the new superconductor UTe2 has been investigated for the first time at low temperature (LT) of 2.7 K, just closely above the superconducting transition temperature of about 1.7 K by single crystal neutron diffraction, in order ... More
Extreme magnetic field-boosted superconductivityMay 10 2019Applied magnetic fields underlie exotic quantum states, such as the fractional quantum Hall effect and Bose-Einstein condensation of spin excitations. Superconductivity, on the other hand, is inherently antagonistic towards magnetic fields. Only in rare ... More
The thermal Hall conductance of a symmetry-breaking topological insulatorMay 10 2019In this note we point out that a model proposed by Hsu, Raghu and Chakravarty[1] has the potential to explain the unusual thermal Hall effect reported in Ref.[2]. This model describes a topological insulator that breaks the spin rotation and point group ... More
Muon spin rotation study of type-I superconductivity: elemental $β-$SnMay 10 2019The application of the muon-spin rotation/relaxation ($\mu$SR) technique for studying type-I superconductivity is discussed. In the intermediate state, i.e. when a type-I superconducting sample with non-zero demagnetization factor $N$ is separated into ... More
Tunable Microwave Single-photon Source Based on Transmon Qubit with High EfficiencyMay 10 2019Single-photon sources are of great interest because they are key elements in different promising applications of quantum technologies. Here we demonstrate a highly efficient tunable on-demand microwave single-photon source based on a transmon qubit with ... More
Distinct Superconducting Gap on Two Bilayer-Split Fermi Surface Sheets in $Bi_2Sr_2CaCu_2O_{8+δ}$ SuperconductorMay 10 2019High resolution laser-based angle-resolved photoemission measurements were carried out on an overdoped $Bi_2Sr_2CaCu_2O_{8+\delta}$ superconductor with a Tc of 75 K. Two Fermi surface sheets caused by bilayer splitting are clearly identified with rather ... More
Magnetic-Field-Induced Phenomena in the Paramagnetic Superconductor UTe$_{2}$May 10 2019We present magnetoresistivity measurements on the heavy-fermion superconductor UTe$_{2}$ in pulsed magnetic fields $\mu_0H$ up to 68~T and temperatures $T$ from 1.4 to 80~K. Magnetic fields applied along the three crystallographic directions $\mathbf{a}$ ... More
The effect of non-superconducting dopants (Mn, V, Cr and Cu) on the nematic fluctuations in iron-based superconductorsMay 10 2019We have systematically studied the nematic susceptibility in non-superconducting Ba(Fe$_{1-x}$TM$_{x}$)$_2$As$_2$ (TM = Cr, Mn, V and Cu) by measuring the uniaxial pressure dependence of the resistivity along the Fe-As-Fe direction. The nematic susceptibilities ... More
Periodicity of magnetization reversals in $\varphi_0$ Josephson junctionMay 10 2019The magnetization reversal in ${\varphi_0}$-Josephson junction with direct coupling between magnetic moment and Josephson current has been studied. By adding pulse signal, the dynamics of magnetic moment components have been simulated and the full magnetization ... More
Superconductivity of surfaces, edges and vertices in systems with imbalanced fermionsMay 09 2019We describe boundary effects in superconducting systems with Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superconducting instability, using Bogoliubov-de-Gennes and Ginzburg-Landau formalisms. Firstly, we show that in dimensions larger than one the standard ... More
Implicit renormalization approach to the problem of Cooper instabilityMay 09 2019In the vast majority of cases, superconducting transition takes place at exponentially low temperature $T_c$ out of the Fermi liquid regime. We discuss the problem of determining $T_c$ from known system properties at temperatures $T \gg T_c$, and stress ... More
Local flux-flow instability in superconducting films near TcMay 09 2019Larkin and Ovchinnikov established that the viscous flow of magnetic flux quanta in current-biased superconductor films placed in a perpendicular magnetic field can lose stability due to a decrease in the vortex viscosity coefficient $\eta$ with increasing ... More
Exotic Cooper pairing in multi-orbital models of Sr$_2$RuO$_4$May 09 2019May 13 2019The unconventional superconductivity in Sr$_2$RuO$_4$ continues to defy a unified interpretation. In this paper, we focus on some novel aspects of its superconducting pairing by exploiting the orbital degree of freedom in this material. The multi-orbital ... More
Exotic Cooper pairing in multi-orbital models of Sr$_2$RuO$_4$May 09 2019The unconventional superconductivity in Sr$_2$RuO$_4$ continues to defy a unified interpretation. In this paper, we focus on some novel aspects of its superconducting pairing by exploiting the orbital degree of freedom in this material. The multi-orbital ... More
Domain wall pinning and hard magnetic phase in Co-doped bulk single crystalline Fe3GeTe2May 09 2019We report the effects of cobalt doping on the magnetic properties of two-dimensional van der Waals ferromagnet Fe3GeTe2. Single crystals of (Fe{1-x}Cox)3GeTe2 with x=0-0.78 were successfully synthesized and characterized with x-ray diffraction, energy ... More
Optically Tailored Trapping Geometries for Ultracold Atoms on a Type-II Superconducting ChipMay 09 2019Superconducting atom chips have very significant advantages in realizing trapping structures for ultracold atoms compared to conventional atom chips. We extend these advantages further by developing the ability to dynamically tailor the superconducting ... More
Cavity Higgs-PolaritonsMay 08 2019Motivated by the dramatic success of realizing cavity exciton-polariton condensation in experiment we consider the formation of polaritons from cavity photons and the amplitude or Higgs mode of a superconductor. Enabled by the recently predicted and observed ... More
Tuning from Frustrated Magnetism to Superconductivity in Quasi-One-Dimensional KCr$_3$As$_3$ Through Hydrogen DopingMay 08 2019We report the charge doping of KCr$_3$As$_3$ via H intercalation. We show that the previously reported ethanol bath deintercalation of K$_2$Cr$_3$As$_3$ to KCr$_3$As$_3$ has a secondary effect whereby H from the bath enters the quasi-one-dimensional Cr$_6$As$_6$ ... More
Superconducting gap anisotropy and topological singularities due to lattice translational symmetry and their thermodynamic signaturesMay 08 2019Symmetry arguments based on the point group of a system and thermodynamic measurements are often combined to identify the order parameter in unconventional superconductors. However, lattice translations, which can induce additional momenta with vanishing ... More
Superconducting boron doped nanocrystalline diamond on boron nitride ceramicsMay 08 2019In this work we have demonstrated the growth of nanocrystalline diamond on boron nitride ceramic. We measured the zeta potential of the ceramics to select the diamond seeds. Diamond was then grown on the seeded ceramics using a microwave chemical vapour ... More
The Strange Metal State of the Electron-Doped CupratesMay 07 2019An understanding of the high-temperature copper oxide (cuprate) superconductors has eluded the physics community for over thirty years, and represents one of the greatest unsolved problems in condensed matter physics. Particularly enigmatic is the normal ... More
Metallic and insulating stripes and their relation with superconductivity in the doped Hubbard modelMay 07 2019The dualism between superconductivity and charge/spin modulations (the so-called stripes) dominates the phase diagram of many strongly-correlated systems. A prominent example is given by the Hubbard model, where these phases compete and possibly coexist ... More
Orbital Symmetry and Orbital Excitations in High-$T_c$ SuperconductorsMay 07 2019We discuss a few possibilities of high-$T_c$ superconductivity with more than one orbital symmetry contributing to the pairing. First, we show that the high energies of orbital excitations in various cuprates suggest a simplified model with a single orbital ... More
Double-Core Vortex Stabilized by Disorder in Superfluid $^3$He B Phase in Globally Isotropic AerogelMay 07 2019In a p-wave Fermi superfluid suffering from the nonmagnetic impurity scatterings, a coefficient of a gradient term becomes divergent upon cooling. Consequences of this divergent rigidity in the stable vortices in the B phase in globally isotropic aerogel ... More
Braiding Flux-Tubes in a Topological Lattice Model from Class-DMay 07 2019We use magnetic flux-tubes to stabilize zero-energy modes in a lattice realization of a 2-dimensional superconductor from class D of classification table of topological condensed matter systems. The zero modes are exchanged by slowly displacing the flux-tubes ... More
Nonsaturating magnetoresistance and nontrivial band topology of type-II Weyl semimetal NbIrTe4May 07 2019Weyl semimetals, characterized by nodal points in the bulk and Fermi arc states on the surface, have recently attracted extensive attention due to the potential application on low energy consumption electronic materials. In this report, the thermodynamic ... More
Effect of structural supermodulation on superconductivity in tri-layer cuprate Bi2Sr2Ca2Cu3O10+xMay 07 2019We investigate the spatial and doping evolutions of the superconducting properties of tri-layer cuprate Bi2Sr2Ca2Cu3O10+x by using scanning tunneling microscopy and spectroscopy. Both the superconducting coherence peak and gap size exhibit periodic variations ... More
Quasiparticle interference and charge order in a heavily overdoped non-superconducting cuprateMay 07 2019One of the key issues in unraveling the mystery of high Tc superconductivity in the cuprates is to understand the normal state outside the superconducting dome. Here we perform scanning tunneling microscopy and spectroscopy measurements on a heavily overdoped, ... More
Visualizing the periodic modulation of Cooper pairing in a severely underdoped cuprateMay 07 2019A major obstacle in understanding the mechanism of Cooper pairing in the cuprates is the existence of various intertwined orders associated with spin, charge, and Cooper pairs. Of particular importance is the ubiquitous charge order features that have ... More
Instabilities of the normal state in current-biased narrow superconducting stripsMay 07 2019We study the current-voltage characteristic of narrow superconducting strips in the gapless regime near the critical temperature in the framework of the Ginzburg-Landau model. Our focus is on its instabilities occurring at high current biases. The latter ... More
Specific heat maximum as a signature of Mott physics in the two-dimensional Hubbard modelMay 06 2019Recent experiments on cuprates show that as a function of doping, the normal-state specific heat sharply peaks at the doping $\delta^*$, where the pseudogap ends at low temperature. This finding is taken as the thermodynamic signature of a quantum critical ... More
Quantum oscillations from networked topological interfaces in a Weyl semimetalMay 06 2019Layered transition metal chalcogenides are promising hosts of electronic Weyl nodes and topological superconductivity. MoTe$_2$ is a striking example that harbors both noncentrosymmetric T$_d$ and centrosymmetric T' phases, both of which have been identified ... More
Chiral superconductivity in the alternate stacking compound 4Hb-TaS$_2$May 06 2019Layered van der Waals (vdW) materials are emerging as one of the most versatile directions in the field of quantum condensed matter physics. They allow an unprecedented control of electronic properties via stacking of different types of two-dimensional ... More
Chiral superconductivity in the alternate stacking compound 4Hb-TaS$_2$May 06 2019May 13 2019Layered van der Waals (vdW) materials are emerging as one of the most versatile directions in the field of quantum condensed matter physics. They allow an unprecedented control of electronic properties via stacking of different types of two-dimensional ... More
Twist-angle dependence of electron correlations in moiré graphene bilayersMay 06 2019Motivated by the recent observation of correlated insulator states and unconventional superconductivity in twisted bilayer graphene, we study the dependence of electron correlations on the twist angle and reveal the existence of strong correlations over ... More
Observation of clean conventional Caroli-de Gennes-Matricon states in the vortex core of single-layer FeSe/SrTiO3May 06 2019Using low-temperature scanning tunneling microscopy (STM), we studied the vortex states of single-layer FeSe film on SrTiO3 (100) substrate, and the local behaviors of superconductivity at sample boundaries. We clearly observed multiple discrete Caroli-de ... More
Topological nodal lines and hybrid Weyl nodes in YCoC$_2$May 05 2019Based on first-principles calculations and effective model analysis, we propose that the noncentrosymmetric superconductor YCoC$_2$ in normal state is a topological semimetal. In the absence of spin-orbit coupling (SOC), it can host two intersecting nodal ... More
$Z_3$-vestigial nematic order due to superconducting fluctuations in the doped topological insulator Nb$_x$Bi$_2$Se$_3$May 05 2019A state of matter with a multi-component order parameter can give rise to a vestigial order. In the vestigial phase, the primary order is only partially melted, leaving a remaining symmetry breaking behind, an effect driven by strong classical or quantum ... More
High-frequency size effect study of the Fermi surface of metalsMay 05 2019This paper reviews experimental and theoretical works on the study of the Fermi surface of pure metals with the aid of high-frequency size effects. Particular attention is given to little-known new ballistic effects such as the time of flight effect, ... More
Collective modes in two dimensional topological superconductorsMay 05 2019Collective modes in two dimensional topological superconductors are studied by an extended random phase approximation theory while considering the influence of vector field of light. In two situations, the s-wave superconductors without spin-orbit-coupling ... More
Two-tone spectroscopy of a SQUID metamaterial in the nonlinear regimeMay 04 2019Compact microwave resonantors made of superconducting rings containing Josephson junctions (SQUIDs) are attractive candidates for building frequency tunable metamaterials with low losses and pronounced nonlinear properties. We explore the nonlinearity ... More
Exotic pairing state in quasicrystalline superconductors under magnetic fieldMay 04 2019We theoretically study the effect of a magnetic field on quasicrystalline superconductors, by modelling them as the attractive Hubbard model on the Penrose-tiling structure. We find that at low temperatures and under a high magnetic field there appears ... More
Superconducting properties and topological nodal line signatures in centrosymmetric compound SnTaS$_2$May 04 2019We report the magnetization, electrical resistivity, specific heat measurements and band structure calculations of layered superconductor SnTaS$_2$. The experiments are performed on single crystals grown by chemical vapor transport method. The resistivity ... More
Disappearance of Superconductivity Due to Vanishing Coupling in the Overdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$May 03 2019In high-temperature cuprate superconductors, superconductivity is accompanied by a "plethora of orders", and phenomena that may compete, or cooperate with superconductivity, but which certainly complicate our understanding of origins of superconductivity ... More
Prospects to attain room temperature superconductivityMay 03 2019With a generic model for the electron-phonon spectral density, two simple expressions are derived to estimate the transition temperature and gap-to-temperature ratio in conventional superconductors. They entail that on average the numerical value of the ... More
The superconducting order parameter of Sr$_2$RuO$_4$: a microscopic perspectiveMay 03 2019The character of the superconducting phase of Sr$_2$RuO$_4$, is topic of a longstanding discussion. The classification of the symmetry allowed order parameters has relied on the tetragonal symmetry of the lattice and on cylindrical Fermi surfaces, usually ... More
Non-linear $IV$ characteristics in two-dimensional superconductors: Berezinskii-Kosterlitz-Thouless physics vs inhomogeneityMay 03 2019One of the hallmarks of the Berezinskii-Kosterlitz-Thouless (BKT) transition in two-dimensional (2D) superconductors is the universal jump of the superfluid density, that can be indirectly probed via the non-linear exponent of the current-voltage $IV$ ... More
Comprehensive Eliashberg analysis of microwave conductivity and penetration depth of K-, Co-, and P-substituted BaFe2As2May 03 2019We report on the combined experimental and theoretical analysis of the microwave-frequency electromagnetic response of BaFe2As2 single crystals with different substitutions: K in the Ba site (hole doping), Co in the Fe site (electron doping), and P in ... More
Odd-frequency superconducting pairing in Kitaev-based junctionsMay 03 2019We investigate odd-frequency superconducting correlations in normal-superconductor (NS) and short superconductor-normal-superconductor (SNS) junctions with the S region described by the Kitaev model of spinless fermions in one dimension. We demonstrate ... More
Absence of a dissipative quantum phase transition in Josephson junctionsMay 03 2019May 06 2019Half a century after its discovery, the Josephson junction has become the most important nonlinear quantum electronic component at our disposal. It has helped reshaping the SI system around quantum effects and is used in scores of quantum devices. By ... More
Engineering nodal topological phases in Ising superconductors by magnetic superstructuresMay 03 2019Recently it was discovered that superconductivity in transition metal dichalcogenides (TMDs) is strongly affected by an out-of-plane spin-orbit coupling (SOC). In addition, new techniques of fabricating 2d ferromagnets on van der Waals materials are rapidly ... More
Evidence of quantum vortex fluid in the mixed state of very weakly pinned a-MoGe thin filmsMay 03 2019Quantum fluids refer to a class of systems that remain in the fluid state down to absolute zero temperature. In this paper, using a combination of magnetotransport and scanning tunneling spectroscopy down to 300 mK, we show that vortices in very weakly ... More
Towards searching for Majorana fermions in topological insulator nanowiresMay 03 2019Developing a gate-tunable, scalable, and topologically-protectable supercurrent qubit and integrating it into a quantum circuit are crucial for applications in the fields of quantum information technology and topological phenomena. Here we propose that ... More
Odd-frequency superconductivity induced by non-magnetic impuritiesMay 02 2019A growing body of literature suggests that odd-frequency superconducting pair amplitudes can be generated in normal metal-superconductor junctions. The emergence of odd-frequency pairing in these systems is often attributed to the breaking of translation ... More
p-Wave Superconductivity in Iron-based SuperconductorsMay 01 2019The possibility of p-wave pairing in superconductors has been proposed more than five decades ago, but has not yet been convincingly demonstrated. One difficulty is that some p-wave states are thermodynamically indistinguishable from s-wave, while others ... More
Scalable Majorana vortex modes in iron-based superconductorsApr 30 2019A vortex in an s-wave superconductor with a surface Dirac cone can trap a Majorana bound state with zero energy leading to a zero-bias peak (ZBP) of tunneling conductance. The iron-based superconductor FeTe$_x$Se$_{1-x}$ is one of the material candidates ... More
Possible Topological Phase Transition in Fe-Vacancy-Ordered $β$-Fe$_{4+δ}$Se$_{5}$ NanowiresApr 30 2019We studied the electrical transport on $\beta$-Fe$_{4+\delta}$Se$_{5}$ single-crystal nanowires, exhibiting $\sqrt{5}\times\sqrt{5}$ Fe-vacancy order and mixed valence of Fe. We observed a first-order metal-insulator transition of the transition temperature ... More
Thermal flux-flow regime in long Josephson tunnel junctionsApr 30 2019We study thermal transport induced by soliton dynamics in a long Josephson tunnel junction operating in the flux-flow regime. A thermal bias across the junction is established by imposing the superconducting electrodes to reside at different temperatures, ... More
Superconductivity of strongly correlated electrons on the honeycomb latticeApr 30 2019A microscopic theory of the electronic spectrum and of superconductivity within the t-J model on the honeycomb lattice is developed. We derive the equations for the normal and anomalous Green functions in terms of the Hubbard operators by applying the ... More
Moiré with flat bands is differentApr 30 2019Recent experimental discoveries of superconductivity and other exotic electronic states in twisted bilayer graphene (TBG) call for a reconsideration of our traditional theories of these states, usually based on the assumption of the presence of a Fermi ... More
Moiré with flat bands is differentApr 30 2019May 02 2019Recent experimental discoveries of superconductivity and other exotic electronic states in twisted bilayer graphene (TBG) call for a reconsideration of our traditional theories of these states, usually based on the assumption of the presence of a Fermi ... More
Incoherent-coherent crossover and the pseudogap in Te-annealed superconducting Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ revealed by magnetotransport measurementsApr 30 2019In this study, we conducted various magnetotransport measurements on Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ single crystals from which excess iron was sufficiently removed. Our results revealed that crossover from the incoherent to the coherent electronic state ... More
Orbital symmetries of charge density wave order in YBa2Cu3O6+xApr 29 2019Charge density wave (CDW) order has been shown to compete and co-exist with superconductivity in underdoped cuprate superconductors. Theoretical proposals for the CDW order include an unconventional d-symmetry form factor CDW -- a quadrupolar modulation ... More