超导电性
We discuss intrinsic relaxation rates in superconductors, and how they may be measured using non-linear optical (terahertz) response. We consider both $s$ and $d$-wave superconductors, both with and without a phenomenological (energy…
Real band topology often appears in systems with space-time inversion symmetry and is characterized by invariants such as the Euler and second Stiefel-Whitney classes. Here, we examine the generic band topology of Bogoliubov de-Gennes (BdG)…
Hybrid superconductor/semiconductor devices play a crucial role in advancing quantum science and technology by merging the properties of superconductors and semiconductors. To operate these devices at high temperature, Niobium could…
We investigate the possible pairing symmetry of superconducting $\rm{BaPtAs}_{1-\it{x}}\rm{Sb}_{\it{x}}$ solid solution with an ordered-honeycomb network of Pt and pnictogens. A spontaneous internal magnetic field below the superconducting…
The topological semimetal YPtBi has attracted considerable attention, owing to its novel superconducting and normal state properties. A strong band inversion from spin-orbit coupling allows the existence of $j=3/2$ quasiparticles near the…
Angle-resolved photoemission spectroscopy (ARPES) directly probes the energy and momentum of electrons in quantum materials, but conventional setups capture only a small fraction of the full 2$\pi$ solid angle. This limitation is acute in…
We report large $\pi$-state critical current densities, $J_c(\pi)$, in Nb/Pd$_{89}$Ni$_{11}$/Nb Josephson junctions at Pd$_{89}$Ni$_{11}$ thicknesses near the first $\pi$-state. We observe oscillations in the critical current with…
The pairing mechanism behind the monolayer FeSe is one essential question for iron-based superconductors. In this work, we show the sublattice degree of freedoms of monolayer FeSe plays a special role in its pairing properties, namely the…
Niobium is a practical material platform for superconducting microwave circuits; however, device-level performance can vary significantly depending on film growth and processing conditions. We compare three epitaxial Nb films grown on…
We introduce a zero-bias superconducting voltage amplifier that harvests energy from a thermal gradient by exploiting negative differential resistance (NDR) in an asymmetric tunnel junction. The device is based on an asymmetric…
We report reproducible magnetization anomalies appearing below room temperature in copper-doped apatite materials belonging to the LK-99 family synthesized via hydrothermal methods. These anomalies are observed consistently across samples…
Superconductivity and nematicity coexist in the phase diagram of many correlated systems, including iron-based superconductors. We investigate how Hund-driven correlations reshape boson-mediated superconductivity in a multiorbital nematic…
We propose an explanation of the observed dependence of the maximal critical temperature $T_{c,max}$ on the number of conducting layers $n$ in layered copper-oxide superconductors within the preformed pair mechanism. Copper-oxygen planes…
Control of oxygen vacancies by electrical currents in complex oxides such as YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) has attracted considerable interest due to the relative simplicity of its implementation and its potential for both fundamental…
Behavior of the Grand thermodynamic potential along with its derivatives, entropy and specific heat, is considered within a two-band model of an unconventional $s_\pm$ superconductor with nonmagnetic impurities. The transition $s_\pm \to…
For the BCS theory of superconductivity, the electron-phonon interaction is transformed to an attractive electron-electron interaction in the vicinity of the Fermi energy only. At the same time, its formal derivation using a unitary…
Binary Bi-Pd/Pt systems have attracted a lot of interest because of their topologically non-trivial nature along with superconductivity. We report the structural and superconducting properties of high-quality single-crystalline BiPt using a…
The effect of spin-orbit coupling in a Josephson diode has not been elucidated due to its interplay with the complexity of Josephson devices. Here, we systematically control local electric fields in epitaxial Al-InAs Josephson junctions…
Superconducting nanowire single-photon detectors are widely used in various fields of physics and technology, due to their high efficiency and timing precision. Although, in principle, their detection mechanism offers broadband operation,…
The thermodynamic critical field $B_{\rm c}$ provides direct access to the superconducting condensation energy, yet its pressure dependence has been studied much less extensively than that of the transition temperature. Here,…