Related papers: Multiple phase transitions in Pauli limited iron-b…
More than a quarter century after the discovery of the high temperature superconductor (HTS) YBa$_2$Cu$_3$O$_{6+\delta}$ (YBCO) studies continue to uncover complexity in its phase diagram. In addition to HTS and the pseudogap there is…
The persistent current in small isolated rings enclosing magnetic flux is the current circulating in equilibrium in the absence of an external excitation. While initially studied in superconducting and normal metals, recently, atomic…
Experimental evidence of superconductors with critical temperatures above $373\:K$ is presented. In a family of different compounds we demonstrate the superconductor state, the transition to normal state above $387\:K$, an intermediate…
High temperature superconductivity is a property of doped antiferromagnetic insulators. The electronic structure is inhomogeneous on short length and time scales, and, as the temperature decreases, it evolves via two crossovers, before long…
The magnetic field and temperature dependencies of the magnetic moments of superconducting crystals of ${\rm V_{3}Si}$ have been studied. In a constant magnetic field and at temperatures somewhat below the superconducting transition…
Highly disordered superconductors, in the magnetic-field-driven insulating state, can show discontinuous current-voltage characteristics. Electron overheating has been shown to give a consistent description of this behavior, but there are…
We apply the generalized two-band model of superconductivity to calculate the electronic contribution to the specific heat, superconducting gaps and electron-boson coupling constants of the multi-band layered superconductors MgB2 and…
Recent experiments on K$_3$C$_{60}$ and layered copper-oxide materials have reported substantial changes in the optical response following application of an intense THz pulse. These data have been interpreted as the stimulation of a…
We present a microscopic study of the behavior of the order parameters near boundaries of a two-band superconducting material, described by the standard tight-binding Bardeen-Cooper-Schrieffer model. We find superconducting surface states.…
After a brief introduction to crystalline organic superconductors and metals, we shall describe two recently-observed exotic phases that occur only in high magnetic fields. The first involves measurements of the non-linear electrical…
Quantum dots attached to BCS superconducting leads exhibit a $0-\pi$ impurity quantum phase transition, which can be experimentally controlled either by the gate voltage or by the superconducting phase difference. For the pertinent…
The possibility of a superradiant phase transition in light-matter systems is the subject of much debate, due to numerous apparently conflicting no-go and counter no-go theorems. Using an arbitrary gauge approach we show that a unique phase…
The study of liquid-gas phase transition in heavy ion collisions has generated a lot of interest amongst the nuclear physicists in the recent years. In heavy ion collisions, there is no direct way of measuring the state variables like…
We present magnetic torque, specific heat and thermal expansion measurements combined with a piezo rotary positioner of the bulk transition metal dichalcogenide (TMD) superconductor NbS2 in high magnetic fields applied strictly parallel to…
Dissipation inevitably occurs in first order phase transitions, leading to the irreversible heating. Conversely, the irreversible heating effect could be a clue for the first order phase transition. We measured the temperature change at the…
Topological superconductivity is an exotic quantum phenomenon with coupled nontrivial topological order and superconductivity together. A direct idea for producing topological superconductors is to create superconductivity based on the well…
Following the discovery of superconductivity in epsilon-iron, subsequent experiments hinted at non-Fermi liquid behaviour of the normal phase and sensitive dependence of the superconducting state on disorder, both signatures of…
Lee, Kim, and coworkers have recently claimed room-temperature and ambient-pressure superconductivity in a copper-doped lead apatite material named LK-99. However, the polycrystalline material synthesized has a significant fraction of…
We study superconductivity in paramagnetic and ferromagnetically-ordered phases in a two-dimensional electron system with parabolic fermionic dispersion and short-range repulsive interaction. In the paramagnetic phase, we find that a weak…
The response of superconducting aluminum to electromagnetic radiation is investigated in a broad frequency (45 MHz to 40 GHz) and temperature range ($T>T_c/2$), by measuring the complex conductivity. While the imaginary part probes the…