Related papers: Multiple fluxoid transitions in mesoscopic superco…
We use a quantum Monte Carlo method to study the ground state and thermodynamic phase transitions of the spin supersolid phase in the S=1 Heisenberg model with uniaxial anisotropy. The thermal melting of the supersolid phase shows unqiue…
The superconducting phase diagram of MgB2 was determined from magnetization, magneto-transport and the first single-crystal specific heat measurements. A zero-temperature in-plane coherence length of 8 nm is determined. The superconducting…
The finite-temperature phase diagram of the attractive Hubbard model is studied by means of the Dynamical Mean Field Theory. We first consider the normal phase of the model by explicitly frustrating the superconducting ordering. In this…
We report on a fully self-consistent determination of a phase transition to a superconducting state in a conserving approximation. The transition temperature calculated for a two-dimensional Hubbard model with an attractive interaction in…
In a micro ring of a superconductor with a spin-triplet equal-spin pairing state, a fluxoid, a combined object of magnetic flux and circulating supercurrent, can penetrate as half-integer multiples of the flux quantum. A candidate material…
Em geral, quando a teoria fenomenol\'ogica de Ginzburg-Landau para supercondutores \'e trabalhada, pouco se esclarece aos alunos sobre a origem da mesma. Esta tem como base conceitos termodin\^amicos como fen\^omenos cr\'iticos e…
We present a theoretical survey of ferromagnetic transition temperatures in cubic (III,Mn)V semiconductors based on a model with $S=5/2$ local moments exchange-coupled to itinerant holes in the host semiconductor valence band. Starting from…
First-order phase transition in a highly correlated electron system can manifest as a dynamic phenomenon. The presence of multiple domains of the coexisting phases average out the dynamical effects making it nearly impossible to predict the…
Unusual metallic states involving breakdown of the standard Fermi-liquid picture of long-lived quasiparticles in well-defined band states emerge at low temperatures near correlation-driven Mott transitions. Prominent examples are…
We discuss the occurrence of crossing points in the magnetization - temperature $(m,T$) plane within the framework of critical phenomena. It is shown that in a two-dimensional superconducting slab of thickness $d_{s}$ $m_{z}(\delta)$ versus…
We examine the effect of classical magnetic fluctuations on the phase diagram of paramagneticallylimited two-dimensional superconductors under a Zeeman magnetic field. We derive the free energy expansion in powers of the superconducting…
A microscopic mean-field theory of the phase coexistence between ferromagnetism and superconductivity in the weakly ferromagnetic itinerant electron system is constructed, while incorporating a realistic mechanism for superconducting…
Conventional superconductors have vortices carrying integer multiples of magnetic flux quantum while unconventional ones, with p- or d-wave order parameter, allow half-integer fluxes. Here we show that mesoscopic size effects stabilize…
In normal mesoscopic metals of a ring topology persistent currents can be induced by threading the center of the ring with a magnetic flux. This phenomenon is an example of the famous Aharonov-Bohm effect. In the paper we study the current…
We investigate the interplay between the magnetic and the superconducting degrees of freedom in unconventional multi-band superconductors such as iron pnictides. For this purpose a dynamical mode-mode coupling theory is developed based on…
When a superconducting ring encloses a magnetic flux that is not an integer multiple of half the quantum of flux, a voltage arises in the direction perpendicular to the temperature gradient. This effect is entirely due to thermal…
We investigate superconducting phase transition in superconductor(S)/ferromagnet(F) bilayer with Rasba spin-orbit interaction at S/F interface. This spin-orbit coupling produces spontaneous supercurrents flowing inside the atomic-thickness…
We consider a superconductor-ferromagnet (S/F) structure and assume that above the superconducting transition temperature $T_{c}$ the magnetic moment exists only in F. {In a simple model of the ferromagnet (the exchange field is of the…
The dual approach to the Ginzburg-Landau theory of a Bardeen-Cooper-Schrieffer superconductor is reviewed. The dual theory describes a grand canonical ensemble of fluctuating closed magnetic vortices, of arbitrary length and shape, which…
Within the micro-canonical ensemble phase transitions of first order can be identified without invoking the thermodynamic limit. We show for the liquid-gas transition of sodium, potassium, and iron at normal pressure that the transition…