Related papers: Pauli-Limited Superconductivity with Classical Mag…
We investigate the impact of quantum and thermal phase fluctuations on the suppression of superconducting order in two-dimensional systems. Within the two-dimensional quantum XY model in the phase representation, where on-site interaction…
We investigate diamagnetic fluctuations in percolating granular superconductors. Granular superconductors are known to have a rich phase diagram including normal, superconducting and spin glass phases. Focusing on the normal-superconducting…
Superconductivity in three dimensions is almost universally governed by Ginzburg-Landau mean field theory, with critical fluctuations typically confined to within a few percent of the transition temperature ($T_{\rm c}$). We report that the…
Motivated by recent experiments reporting superconductivity only at very low temperature in a class of heavy fermion compounds, we study the impact of energy fluctuations with small momentum transfer on the pairing instability near an…
We study the effects of Fermi-liquid interactions on quasi-two-dimensional d-wave superconductors in a magnetic field. The phase diagram of the superconducting state, including the periodic Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in…
We investigate the influence of Landau quantization on the superconducting instability for a pure layered superconductor in the magnetic field directed perpendicular to the layers. We demonstrate that the quantization corrections to the…
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…
Superconducting fluctuations (SF) in SmFeAsO$_{0.8}$F$_{0.2}$ (characterized by superconducting transition temperature $T_{c} \simeq 52.3$ K) are investigated by means of isothermal high-resolution dc magnetization measurements. The…
We propose a thermodynamic model of free energy expansion up to eighth order of magnetisation to describe the complex magnetic phase transitions in ferromagnetic superconductor UGe$_2$. The model successfully describes transitions between…
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…
In the framework of the Ginzburg-Landau equation, the temperature dependence of the upper critical field of small ring-like superconductors is studied. At equilibrium small parts of the phase diagram show paramagnetism for width / radius…
We report results of a Monte Carlo study of doped, diluted magnetic semiconductors in the low carrier density (insulating) regime. We find that the system undergoes a transition from a paramagnet at high temperatures to a ferromagnet at low…
Several unconventional superconducting phases have been discovered close to a metamagnetic transition in the heavy-fermion compound UTe$_2$. Although suspected to be of magnetic nature, the mechanisms stabilizing these superconducting…
Superconductor insulator transition in transverse magnetic field is studied in the highly disordered MoC film with the product of the Fermi momentum and the mean free path $k_F*l$ close to unity. Surprisingly, the Zeeman paramagnetic…
The excess Hall conductivity, resulting from thermal fluctuations of the superconducting order parameter, is calculated for a layered superconductor for an arbitrarily strong in-plane electric field and a perpendicular magnetic field in the…
We calculate fluctuation corrections to the longitudinal conductivity of disordered superconductors subject to an external magnetic field. We derive analytic expressions that are valid in the entire metallic part of the temperature-magnetic…
Recently discovered superconducting P-doped EuFe$_2$As$_2$ compounds reveal the situation when the superconducting critical temperature substantially exceeds the ferromagnetic transition temperature. The main mechanism of the interplay…
We have investigated the magnetic phase diagram near the upper critical field of KFe2As2 by magnetic torque and specific heat experiments, using a high-resolution piezo-rotary positioner to precisely control the parallel orientation of the…
The normal state and superconducting properties are investigated in the phase diagram of K_xSr_{1-x}Fe_2As_2 for 0<x<1. The ground state upper critical field, H_{c2}(0), is extrapolated from magnetic field dependent resistivity…
We derive the Ginzburg-Landau-Wilson theory for the superconducting phase transition in two dimensions and in the magnetic field. Without disorder the theory describes a fluctuation induced first-order quantum phase transition into the…