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The work is a concept of fundamental importance in thermodynamics. An open question is how to describe the work fluctuation for quantum coherent processes in the presence of initial quantum coherence in the energy basis. With the aim of…

Quantum Physics · Physics 2022-01-05 Gianluca Francica

Temporal fluctuations in the superconducting qubit lifetime, $T_1$, bring up additional challenges in building a fault-tolerant quantum computer. While the exact mechanisms remain unclear, $T_1$ fluctuations are generally attributed to the…

We present a general interpolation theory for the phenomenological effects of thermal fluctuations in superconductors. Fluctuations are described by a simple gauge invariant extension of the gaussian effective potential for the…

Superconductivity · Physics 2007-05-23 L. Marotta , M. Camarda , G. G. N. Angilella , F. Siringo

We derive a generalized version of the work fluctuation theorem for nonequilibrium systems with spatio-temporal temperature fluctuations. For chi-square distributed inverse temperature we obtain a generalized fluctuation theorem based on…

Statistical Mechanics · Physics 2009-11-10 C. Beck , E. G. D. Cohen

Understanding the roles of disorder and superconducting phase fluctuation in superconductivity has been a long-standing challenge. For example, while the phase fluctuation is expected to destroy the superconductivity of intrinsically…

Superconductivity · Physics 2024-10-08 F. Yang , L. Q. Chen

We analyze the applicability of the Fermi-golden-rule description of quasiparticle relaxation in a closed diffusive quantum dot with electron-electron interaction. Assuming that single-particle levels are already resolved but the initial…

Strongly Correlated Electrons · Physics 2016-04-29 Vladyslav A. Kozii , Mikhail A. Skvortsov

A theory of fluctuations in two-band superconductor MgB$_{2}$ is developed. Since the standard Ginzburg-Landau (GL) approach fails in description of its properties, we generalize it basing on the microscopic theory of a two-band…

Superconductivity · Physics 2009-11-10 A. E. Koshelev , A. A. Varlamov , V. M. Vinokur

The shape of experimentally observed R(T) transition of thin superconducting wires is analyzed. Broadening of the transition in quasi-1-dimensional superconducting channels is typically associated with phase slip mechanism provided by…

Superconductivity · Physics 2009-04-07 M. Zgirski , K. Yu. Arutyunov

We discuss a method by which quantum fluctuations can be included in microscopic transport models based on wave packets that are not energy eigenstates. By including the next-to-leading order term in the cumulant expansion of the…

Nuclear Theory · Physics 2009-10-30 A. Ohnishi , J. Randrup

We investigate subgap quasiparticles of a single level quantum dot coupled to the superconducting and normal leads, whose energy level is periodically driven by external potential. Using the Floquet formalism we determine the quasienergies…

Mesoscale and Nanoscale Physics · Physics 2019-08-14 B. Baran , T. Domański

We study the order parameter phase fluctuation effects in cuprate superconductors near T=0, using a quasi-two-dimensional d-wave BCS model. An effective phason theory is obtained which is used to estimate the strength of the fluctuations,…

Superconductivity · Physics 2009-10-31 Hyok-Jon Kwon , Alan T. Dorsey , P. J. Hirschfeld

We study the effects of low-energy nodal quasiparticles on the classical phase fluctuations in a two-dimensional d-wave superconductor. The singularities of the phase-only action at T\to 0 are removed in the presence of disorder, which…

Superconductivity · Physics 2009-11-11 K. V. Samokhin , B. Mitrovic

We argue that quantum fluctuations of the phase of the order parameter may strongly affect the electron density of states (DOS) in ultrathin superconducting wires. We demonstrate that the effect of such fluctuations is equivalent to that of…

Mesoscale and Nanoscale Physics · Physics 2017-09-06 Alexey Radkevich , Andrew G. Semenov , Andrei D. Zaikin

In this tutorial, we present the definition, interpretation and properties of some of the main quasiprobabilities that can describe the statistics of measurement outcomes evaluated at two or more times. Such statistics incorporate the…

Quantum Physics · Physics 2024-09-23 Stefano Gherardini , Gabriele De Chiara

We calculate the sample-to-sample fluctuations in the excitation gap of a chaotic dynamical system coupled by a narrow lead to a superconductor. Quantum fluctuations on the order of magnitude of the level spacing, predicted by random-matrix…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. C. Goorden , Ph. Jacquod , C. W. J. Beenakker

We calculate suppression of inter- and intralayer superconducting currents due to equilibrium phase fluctuations and find that, in contrast to a recent prediction, the effect of thermal fluctuations cannot account for linear temperature…

Superconductivity · Physics 2009-10-31 S. N. Artemenko , S. V. Remizov

We study the effects of quantum fluctuations on the transport properties of multiband superconductors near a pair-breaking quantum critical point. For this purpose, we consider a minimal model of the quantum phase transition in a system…

Superconductivity · Physics 2023-11-28 Maxim Dzero , Maxim Khodas , Alex Levchenko

The problem of a fluctuation-induced first-order transition is considered for $p $-wave superconductors. Both an $\epsilon$-expansion about $d=4$ and a large-$n$ expansion conclude that the transition for the physical case $n=6$ in $d=3$ is…

Superconductivity · Physics 2012-11-20 Qi Li , D. Belitz , John Toner

We derive the fluctuation theorem for quantum-state statistics that can be obtained when we initially measure the total energy of a quantum system at thermal equilibrium, let the system evolve unitarily, and record the quantum-state data…

Statistical Mechanics · Physics 2018-08-01 Naoto Tsuji , Masahito Ueda

The quasiparticle density observed in low-temperature superconducting circuits is several orders of magnitude larger than the value expected at thermal equilibrium. The tunneling of this excess of quasiparticles across Josephson junctions…

Quantum Physics · Physics 2025-11-03 José Alberto Nava Aquino , Rogério de Sousa