Superconductivity
The mechanism of high-temperature superconductivity remains one of the great challenges of contemporary physics. Here, we review efforts to image the vortex lattice in copper oxide-based high-temperature superconductors and to measure the…
We present a microscopic calculation of the inverse Faraday effect in metals. We derive a static local magnetic moment induced on the application of high-frequency light, using the Eilenberger formulation of quasiclassical theory. We…
We prove that multilayer superconductivity with interlayer pairing may naturally decompose into a series of weakly-coupled bilayer and trilayer superconducting blocks in order to minimize its total free energy. Our work is motivated by the…
We study dissipationless spin transport induced by a charge supercurrent in a monolayer van der Waals superconductor under the applied magnetic field and in a bilayer superconductor/ferromagnet (S/F) heterostructure with no external field.…
The recent claim of potential room-temperature superconductivity in Pb$_{10-x}$Cu$_{x}$(PO$_{4}$)$_{6}$O has attracted widespread attention. However, the signature of superconductivity is later attributed to the Cu$_{2}$S impurity formed…
Bloch wave functions of electrons have properties called quantum geometry, which has recently attracted much attention as the origin of intriguing physical phenomena. In this paper, we introduce the notion of the quantum-geometric pair…
The discovery of superconductivity with a critical temperature of about 80~K in La$_{3}$Ni$_{2}$O$_{7}$ single crystals under pressure has received enormous attention. La$_{3}$Ni$_{2}$O$_{7}$ is not superconducting under ambient pressure…
RhBi$_2$ is a polymorphic system that exhibits two distinct phases. RhBi$_2$ in the triclinic phase has been identified as a weak topological insulator with a van Hove singularity point close to the Fermi energy. Thus, triclinic RhBi$_2$ is…
Van der Waals assembly allows for the creation of Josephson junctions in an atomically sharp interface between two exfoliated Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi-2212) flakes that are twisted relative to each other. In a narrow range of…
Usually, overdamped Josephson junctions do not exhibit chaotic behavior in their phase dynamics, either because the phase space dimension is less than three (as in the case of a single overdamped ac-driven junction) or due to the general…
We report superconductivity in the ternary compound IrBi$_{0.8}$Te$_{1.2}$ with critical temperature 1.7 K. The replacement of Bi by Te leads to the metallic conductivity in contrast to the semiconducting parent compound IrBiTe. The…
We review the theoretical model underpinning the recently reported room-temperature, ambient-pressure superconductivity along line defects on the surface of highly-oriented pyrolytic graphite. The main ingredients for this 1D…
Multiple anomalous features in electronic spectra of metals with kagome lattice structure -- van Hove singularities, Dirac points, and flat bands -- imply that materials containing this structural motif may lie at a nexus of topological and…
Using a known distribution of the Meissner currents over the surface of an infinitely long superconducting slab with a rectangular cross section, we find an applied magnetic field at which vortices begin to penetrate into the…
High quality Nb-based superconductor-insulator-superconductor (SIS) junctions with Al oxide (AlO$_x$) tunnel barriers grown from Al overlayers are widely reported in the literature. However, the thin barriers required for high critical…
The unconventional superconductor UTe$_2$ exhibits numerous signatures of spin-triplet superconductivity -- a rare state of matter which could enable quantum computation protected against decoherence. UTe$_2$ possesses a complex phase…
We develop an analytic theory to describe the interaction between electrons and K-phonons and study its influence on superconductivity in the bare bands of twisted bilayer graphene (TBG). We find that, due to symmetry and the two-center…
In this account, we will give an overview of our research progress on novel quantum properties in topological quantum materials with kagome lattice. Here, there are mainly two categories of kagome materials: magnetic kagome materials and…
Nonreciprocal superconductivity, also called as superconducting diode effect that spontaneously breaks time-reversal symmetry, is characterized by asymmetric critical currents under opposite applied current directions. This distinct state…
Based on the energy level structure of neutral oxygen atom O and its anions, through in-depth analysis of the bonding process and formation mechanism of anion O$^{x-}$ ($1<x\leq{2}$) in oxide superconductors dominated by ionic bonds, we…