超导电性
We propose that geometric curvature and torsion may be used to probe the quality of an uncompensated antiferromagnetic interface, using the proximity effect. We study a helix of antiferromagnetic wire coupled to a conventional…
We consider excitation of Higgs modes via the modulation of the BCS coupling within the Migdal-Eliashberg-Keldysh theory of time-dependent superconductivity. Despite the presence of phonons, which break integrability, we observe Higgs…
The discovery of high-temperature superconductivity in bulk La$_3$Ni$_2$O$_7$ under high hydrostatic pressure and, more recently, biaxial compression in epitaxial thin films has ignited significant interest in understanding the interplay…
The electronic structure of pure niobium and the niobium-titanium alloy Nb$_{0.44}$Ti$_{0.56}$ in the bcc-phase at pressures up to $250$ GPa is investigated, to reveal possible factors conducing toward the robust superconductivity reported…
Unconventional superconductivity, where electron pairing does not involve electron-phonon interactions, is often attributed to magnetic correlations in a material. Well known examples include high-T_c cuprates and uranium-based heavy…
This study analyzes the calculation of the critical current density Jc,mag by means of Bean's critical state model, using the equation formulated by Gyorgy et al. and other similar equations derived from it reported in the literature. While…
The vanadium-based kagome metals $A$V$_3$Sb$_5$ ($A$ = K, Rb, and Cs) host a superconducting ground state that coexists with an unconventional charge density wave (CDW). The CDW state exhibits experimental signatures of chirality,…
In this note I apply a theorem of Kohn to quantum oscillations in cuprates. I show that when combined with Gell-Mann and Low theorem, there is rigorous justification of quantum oscillations as in a Fermi liquid for cuprates. The…
We demonstrate in-situ manipulation of the critical temperature ($T_S$) and upper critical field ($H_{C2}$) of conventional and unconventional superconductors via ultrasonic excitation. Using an AC susceptibility measurements, we observed a…
There is evidence for competition between superconductivity and short-range charge-density wave order in a number of cuprate compounds and especially in YBa$_2$Cu$_3$O$_{6+x}$. Here, we use a non-linear sigma model of such competition to…
Layered Nickelates have gained intensive attention as potential high-temperature superconductors, showing similarities and subtle differences to well-known Cuprates. This study introduces a modelling framework to analyze the tunability of…
It is shown that even a weak out-of-plane attraction, V -> 0, can form real-space pairs in the body-centered tetragonal lattice despite the presence of a Hubbard repulsion and a fully developed three-dimensional kinetic energy. In the hole…
Superconducting circuits based on hybrid InAs Josephson Junctions (JJs) play a starring role in the design of fast and ultra-low power consumption solid-state quantum electronics and exploring novel physical phenomena. Conventionally, 3D…
Thermoelectric devices that operate on quantum principles have been under extensive investigation in the past decades. These devices are at the fundamental limits of miniaturized heat engines and refrigerators, advancing the field of…
Spectacular quantum phenomena such as superconductivity often emerge in flat-band systems where Coulomb interactions overpower electron kinetics. Engineering strategies for flat-band physics is therefore of great importance. Here, using…
Recent experiments on 2D superconductors allow the characterization of the critical temperature and of the phase diagram across the BCS-BEC crossover as a function of density. We obtain from these experiments the microscopic parameters of…
A general principle of condensed matter physics prohibits the electric current in equilibrium. This prevents a zero-resistance state realized solely under a finite electric current, namely unidirectional superconductivity. In this paper, we…
Magnetic superconductors manifest a fascinating interplay between their magnetic and superconducting properties. This becomes evident, for example, in the significant enhancement of the upper critical field observed in uranium-based…
Tantalum films incorporated into superconducting circuits have exhibited low surface losses, resulting in long-lived qubit states. Remaining loss pathways originate in microscopic defects which manifest as two level systems (TLS) at low…
The geometrical properties of a helical ferromagnet are shown theoretically to control the critical temperature of a proximity-coupled superconductor. Using the Usadel equation for diffusive spin transport, we provide self-consistent…