36,846 research outputs found
Novel superconductivity: from bulk to nano systems
We begin with an introduction of superconductivity by giving a brief history of the phenomenon. The phenomenological Ginzburg–Landau theory and the microscopic theory of Bardeen, Cooper and Schrieffer are outlined. In view of recently available multi-band superconductors, relevant theories of both types are discussed. Unlike the traditional GL theory an extended GL theory is developed relevant to temperatures below the critical temperature. Superconductivity in a nanosystem is the highlight of the remaining part of the paper. Theories and experiments are discussed to give an interested reader an updated account and overview of what is new in this active area of research
Quasiadiabatic dynamics of ultracold bosonic atoms in a one-dimensional optical superlattice
We study the quasiadiabatic dynamics of a one-dimensional system of ultracold
bosonic atoms loaded in an optical superlattice. Focusing on a slow linear
variation in time of the superlattice potential, the system is driven from a
conventional Mott insulator phase to a superlattice-induced Mott insulator,
crossing in between a gapless critical superfluid region. Due to the presence
of a gapless region, a number of defects depending on the velocity of the
quench appear. Our findings suggest a power-law dependence similar to the
Kibble-Zurek mechanism for intermediate values of the quench rate. For the
temporal ranges of the quench dynamics that we considered, the scaling of
defects depends nontrivially on the width of the superfluid region.Comment: 6 Pages, 4 Figure
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