Superconductivity
For the two-mode electron pairing, we propose a local stacking force pairing mechanism driven by strong local fluctuations, with two straight pairing orbits where the tying Cooper pairing $C_{-k\downarrow}C_{k\uparrow}e^{ik\cdot r}$…
Materials combining topologically non-trivial behavior and superconductivity offer a potential route for quantum computation. However, the set of available materials intrinsically realizing these properties are scarce. Recently, surface…
The recent advent of artificial structures has triggered the emergence of fascinating phenomena that could not exist in natural compounds. A prime example is twisted multilayers, i.e., moir\'e superlattices represented by magic-angle…
Inhomogeneities play a crucial role in determining the properties of quantum materials. Yet methods that can measure these inhomogeneities are few, and apply to only a fraction of the relevant microscopic phenomena. For example, the…
We study non-Hermitian Josephson junctions formed by superconductors with a finite phase difference under non-Hermiticity, which naturally appears due to coupling to normal reservoirs. Depending on the structure of non-Hermiticity, captured…
The interplay between novel topological states and superconductivity has garnered substantial interest due to its potential for topological quantum computing. The Josephson effect serves as a useful probe for edge superconductivity in these…
We report the study of the cocktail effect on superconductivity in high-entropy alloys (HEAs),using hexagonal close-packed HEAs as a prototype system. Compared with the compositional averages of the constituent elements, the superconducting…
Theoretically, Josephson junction (JJ) arrays can exhibit either a superconducting or insulating state, separated by a quantum phase transition (QPT). In this work, we analyzed published data on QPTs in three one-dimensional arrays and two…
Janus transition metal-dichalcogenide (JTMD) materials have attracted a great deal of attention due to their remarkable physical properties arising from the two-dimensional geometry and the breakdown of the out-of-plane symmetry. Using…
Layered transition metal dichalcogenides (TMDs) stabilize in multiple structural forms with profoundly distinct and exotic electronic phases. Interfacing different layer types is a promising route to manipulate TMDs' properties, not only as…
Hidden singularities in correlated electron systems, which are caused by pair fluctuations of electron-electron or electron-hole bubbles obeying Bose-Einstein statistics, are clarified theoretically. The correlation function of each pair…
London and Campbell penetration depths were measured in single crystals of the endohedral gallide cluster superconductor, Mo$_{8}$Ga$_{41}$. The full temperature range superfluid density is consistent with the clean isotropic $s-$wave…
London, $\lambda_L (T)$, and Campbell, $\lambda_{C} (T)$, penetration depths were measured in single crystals of a topological superconductor candidate $\text{AuSn}_4$. At low temperatures, $\lambda_L (T)$ is exponentially attenuated and,…
Measurements of the trapped (remanent) magnetic moment, $M_{trap}\left(H\right)$, when a small magnetic field $H$ is turned off after cooling below the superconducting transition temperature, $T_c$, or ramping a magnetic field up and down…
Inspired by recent remarkable sets of experiments on UTe$_2$: discoveries of the fourth horizontal internal transition line running toward a tetra-critical point (TCP) at $H$=15T, the off-axis high field phases, and abnormally large Knight…
We consider nonreciprocal supercurrent effects in Josephson junctions based on multiband superconductors with a pairing structure that can break time-reversal symmetry. We demonstrate that a nonreciprocal supercurrent can be generally…
Vortex pinning is a crucial factor that determines the critical current of practical superconductors and enables their diverse applications. However, the underlying mechanism of vortex pinning has long been elusive, lacking a clear…
The effect of annealing on the superconducting properties of niobium single crystals cut from the same master boule was studied by local and global magnetic measurements, as well as scanning tunneling microscopy (STM). The formation of…
The striking discovery of high-temperature superconductivity (HTSC) of 80 K in a bilayer nickelate La$_3$Ni$_2$O$_7$ under a moderately high pressure of about 14 GPa ignited a new wave of studying HTSC in nickelates. The properties of the…
Single crystals of Ca$_3$(Ir$_{1-x}$Rh$_x$)$_4$Sn$_{13}$ (3-4-13) were synthesized by flux growth and characterized by X-ray diffraction, EDX, magnetization, resistivity and radio frequency magnetic susceptibility tunnel diode resonator…