Related papers: Upper critical field in ferromagnetic metals with …
Two principles govern the critical temperature for superconducting transitions: (1)~intrinsic strength of the pair coupling and (2)~effect of the many-body environment on the efficiency of that coupling. Most discussions take into account…
We study the effects of an external magnetic field on thensuperconducting phase diagram of a quasi-two-dimensional system of Dirac electrons at an arbitrary temperature. At zero temperature, there is a quantum phase transition connecting a…
We develop a theory of the upper critical field in a BCS superconductor with a nonlocal interaction between electrons. We have shown that the nonlocal interaction is characterized by the parameter $k_F\rho_0$ where $k_F$ is the Fermi…
There is considerable evidence that the heavy fermion material UTe$_2$ is a spin-triplet superconductor, possibly manifesting time-reversal symmetry breaking, as measured by Kerr effect and muon spin resonance experiments below the critical…
We show that above the critical temperature of superconductor - metal phase transitions, both the longitudinal and Hall conductivity exhibit strong temperature dependent mesoscopic fluctuations, with amplitudes much larger than the…
Temperature dependence of the upper critical field $H_{c2}$ of the Dirac semi - metal (DSM) with phonon mediated pairing is considered within semi - classical approximation. The low temperature dependence deviates from conventional BCS…
The spin-triplet state is most likely realized in uranium ferromagnetic superconductors, UGe2, URhGe, UCoGe. The microscopic coexistence of ferromagnetism and superconductivity means that the Cooper pair should be realized under the strong…
In the area of superconducting spintronics, spin triplet supercurrents in half-metallic ferromagnets (HMFs) could yield dissipationless spin transport over large distances, and high current density. Promising among the HMFs is the…
The pressure dependencies of the magnetic and superconducting transitions, as well as that of the superconducting upper critical field are reported for single crystalline EuRbFe$_4$As$_4$. Resistance measurements were performed under…
A microscopic analysis of the superconducting quantum critical point realized via a pair-breaking quantum phase transition is presented. Finite temperature crossovers are derived for the electrical conductivity, which is a key probe of…
Superconductivity in low carrier density metals challenges the conventional electron-phonon theory due to the absence of retardation required to overcome Coulomb repulsion. In quantum critical polar metals, the Coulomb repulsion is heavily…
We review the present status of the experimental and theoretical research on the proximity effect in heterostructures composed of superconducting (S) and ferromagnetic (F) thin films. First, we discuss traditional effects originating from…
An earlier theory of the quantum phase transition in metallic ferromagnets is revisited and generalized in three ways. It is shown that the mechanism that leads to a fluctuation-induced first-order transition in metallic ferromagnets with a…
We propose theoretically that a magnetic field can realize spin-triplet superconductivity in repulsively interacting electron systems having strong ferromagnetic spin fluctuations. We confirm the general idea for the low-density Hubbard…
Recent experiments on certain Fe-based superconductors have hinted at a role for paired electrons in "incipient" bands that are close to, but do not cross the Fermi level. Related theoretical works disagree on whether or not strong-coupling…
We use magnetoresistance measurements at high magnetic field (B \leq 65 T) and low temperature (T \geq 500 mK) to gain fresh insights into the behavior of the upper critical field, Hc2, in superconducting ultrathin FeSe films of varying…
We calculate the spin-drag relaxation rate for a two-component ultracold atomic Fermi gas with positive scattering length between the two spin components. In one dimension we find that it vanishes linearly with temperature. In three…
It is well-known that when the magnetic field is stronger than a critical value, the spin imbalance can break the Cooper pairs of electrons and hence hinder the superconductivity in a spin-singlet channel. In a bilayer system of ultra-cold…
We study a novel type of coupling between spin and orbital degrees of freedom which appears at triplet superconductor-ferromagnet interfaces. Using a self-consistent spatially-dependent mean-field theory, we show that increasing the angle…
Applying the linearized Usadel equations, we consider the nucleation of superconductivity in multiply connected mesoscopic superconductor/ferromagnet (S/F) hybrids such as a thin superconducting ring on a ferromagnet with a uniform in-plane…