超导电性
The single-layer cuprate superconductor HgBa$_{2}$CuO$_{4+\delta}$ (Hg1201) is an ideal candidate for investigating many properties of cuprates with minimal disorder and without the complication of multiple CuO$_2$ layers. Here we measure…
The microscopic origin of supercurrent nonreciprocity in van der Waals Josephson junctions remains under active debate, particularly regarding the role of twist-angle engineering in layered superconductors. Here, we investigate…
The lower critical field \(B_{c1}\) of a narrow superconducting thin-film strip sets the thermodynamic scale for vortex-free operation in a perpendicular magnetic field. The standard Pearl--London estimate requires a phenomenological…
Chiral-structured superconductors, with simultaneous broken mirror and inversion symmetries, promote unconventional superconductivity through parity-mixing mechanisms. Yet a few bulk chiral-structured superconductors are known, partly due…
Motivated by recent observations of superconductivity in a quarter-metal state of spin- and valley- polarized graphene multilayers, we investigate pairing within a ferromagnetic phase of a single-valley model of itinerant two-dimensional…
The superconductivity of CeRh$_2$As$_2$ has drawn attention due to its first-order transition in magnetic fields. At first glance, the multiple superconducting (SC) phases as well as the first-order transition appear consistent with the…
The thiospinel CuIr$_2$S$_4$ undergoes a metal-insulator transition below $\approx$230 K, which is suppressed by substitution of Cu with Zn (Cu$_{1-x}$Zn$_x$Ir$_2$S$_4$) to induce superconductivity for $0.2\lesssim x\lesssim0.8$. We show…
The superconducting diode effect (SDE), characterized by unequal critical supercurrents in opposite current directions, enables supercurrent rectification. We propose a magnetic-field-free pseudo-superconducting-diode effect in…
Hall measurements in superconducting bilayer nickelate films show sign reversals that cannot be explained by rigid-band electron doping alone. We combine a DFT+CDMFT-derived correlated multi-orbital quasiparticle model with a $T$-matrix…
We demonstrate that the polarity of the Josephson diode effect in Corbino Josephson junctions can be deterministically controlled by the vortex number, which arises as a generic consequence of structured spatial inhomogeneity. By solving…
Parity-protected superconducting qubits offer intrinsically long coherence, but many current implementations require magnetic-flux biasing, which introduces flux noise, control overhead, and limited scalability. Here we propose a…
We develop a dynamical description of the superconducting pair field in which the Cooper-channel Hubbard--Stratonovich field $\Delta$ is treated as a memory-dressed Bogoliubov pair field rather than as a purely static order parameter.…
We investigate the effects of isovalent Sb substitution at the As site in fluorine-doped PrFeAs1-xSbxO0.7F0.3 (x = 0 to 1.0) through structural, Raman spectroscopy, density functional theory (DFT), transport, magnetotransport, and magnetic…
We study the Josephson effects in the spin-triplet superconductor/altermagnet/spin-triplet superconductor junctions using the Green's function method. It is found that the current-phase difference relationships in the junctions strongly…
Despite the repulsive Coulomb law and the Pauli statistics that do not favor bound states, attraction between electrons or holes is nevertheless possible in the context of many body interaction and of valley potential landscapes,…
The absorbed power in superconductors driven by a time-dependent external perturbation is investigated through transitions between Bogoliubov quasiparticle states. The transition matrix element contains the superconducting coherence factor,…
Correlated phases of matter are typically investigated in crystalline systems, where disorder is considered to be detrimental. However, intriguing exceptions exist, such as superconductivity being enhanced in amorphous realizations of Al…
Layered PtBi$_2$ is a candidate for topological superconductivity arising in Fermi-arc surface states. Using spin- and angle-resolved photoemission spectroscopy, we demonstrate that the Fermi arcs in PtBi$_2$ are singly degenerate and…
The two-dimensional (2D) limit in macroscopic bulk crystals provides a powerful platform for exploring exotic quantum phases. Here, we report the synthesis of a Sr0.75ClNbS2 superconductor that achieves unidirectional, parallel AA…
The breathing mode in Kagome materials is a structural modulation that breaks inversion symmetry and has been shown to be a crucial source for intriguing phases in the normal state. In this work, we carry out a full classification of…