Related papers: Spontaneous vortex phase discovered?
The finite temperature dynamical phases of vortices in films driven by a uniform force and interacting with the periodic pinning potential of a square lattice of columnar defects are investigated by Langevin dynamics simulations of a London…
We study the spontaneous formation of vortices during the superfluid condensation in a trapped fermionic gas subjected to a rapid thermal quench via evaporative cooling. Our work is based on the numerical solution of the time dependent…
Quantized vortices in type-II superconductors provide insights into the mechanisms of superconductivity. However, the generation of antivortices, characterized by magnetization antiparallel to the external magnetic field, remains less…
Using electron spin resonance (ESR) technique we have obtained data evidencing the existence of magnetic vortices in high-temperature superconductors at temperatures above the critical one $T_c$. We have studied magnetic excitations in \bis…
Competition with magnetism is at the heart of high temperature superconductivity, most intensely felt near a vortex core. To investigate vortex magnetism we have developed a spatially resolved probe using nuclear magnetic resonance. Our…
Symmetry is a basic paradigm for analysis of problems in solid state physics, and to controllably break point-group symmetries is a powerful probe of novel forms of order. In this work, we apply two methods, controlled lattice strain and…
Placing a high-Tc superconductor in an increasing external magnetic field, the flux first penetrates the sample through an Abrikosov vortex lattice, and then a first order transition is observed by which the system goes to the normal phase.…
From magnetisation measurements we provide evidence that the ferromagnetic superconductor RuSr$_{2}$GdCu$_{2}$O$_{8}$ with \QTR{it}{T}$_{c}$=45 K and \QTR{it}{T}$_{M}$=137 K exhibits a sizeable diamagnetic signal at low temperature…
At strong magnetic fields double-layer two-dimensional-electron-gas systems can form an unusual broken symmetry state with spontaneous inter-layer phase coherence. In this paper we explore the rich variety of quantum and finite-temperature…
The sound velocity is measured in polycrystalline MgB2 synthesized from the elements, and the bulk modulus and the Debye temperature are calculated. The conversion of an elastic wave into electromagnetic radiation is investigated in the…
Spontaneous magnetization of a two-dimensional electron gas (2DEG) is discussed. It takes place for sufficiently high electron density (i.e. for a quantum fluid state) with $r_s<10$ which is quite beyond the condition of Wigner…
Three distinct types of behaviour have recently been identified in the two-dimensional trapped bosonic gas, namely; a phase coherent Bose-Einstein condensate (BEC), a Berezinskii-Kosterlitz-Thouless-type (BKT) superfluid and normal gas…
We discuss ultra-cold Fermi gases in two dimensions, which could be realized in a strongly confining one-dimensional optical lattice. We obtain the temperature versus effective interaction phase diagram for an s-wave superfluid and show…
The peak effect in weakly pinned superconductors is accompanied by metastable vortex states. Each metastable vortex configuration is characterized by a different critical current density J_c, which mainly depends on the past thermomagnetic…
At low temperatures and 3He concentrations below 6.6 %, there is experimental evidence about the existence in liquid helium mixtures, of stable vortices with 3He-rich cores. When the system is either supersaturated or submitted to a tensile…
The proximity effect in SF structures was examined. It is shown that, due to the oscillations of the induced superconducting order parameter in a ferromagnet, the critical temperature of an SF-bilayer becomes minimal when the thickness of…
From muon spin rotation measurements on under- to overdoped Bi-2212 crystals we obtain evidence for a two-stage transition of the vortex matter as a function of temperature. The first transition is well known and related to the…
We report on direct measurements of the energy dissipated in the spin-up of the superfluid component of 3He-B. A vortex-free sample is prepared in a cylindrical container, where the normal component rotates at constant angular velocity. At…
The dynamics of the 2D Potts ferromagnet when quenched below the transition temperature is investigated in the case of discontinuous phase transition, which is interesting for understandingthe non equilibrium dynamics of systems with many…
We present a microscopic theory for the low temperature metamagnetic phase diagram of HoNi_2B_2C that agrees well with experiments.For the same model we determined the zero field ground state as a function of temperature and find the…