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Related papers: Finite-frequency noise in a non-interacting quantu…

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We discuss intrinsic mechanisms of nonequilibrium excess noise in superconducting devices and transition edge sensors. In particular, we present an overview of fluctuation-driven contributions to the current noise in the vicinity of the…

Superconductivity · Physics 2023-08-25 Juhun Kwak , Emil Pellett , Elio J. König , Alex Levchenko

We develop the Keldysh formalism for the polarization dynamics of an open spin system. We apply it to the swapping between two qubit states in a model describing an NMR cross-polarization experiment. The environment is a set of interacting…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Ernesto P. Danieli , Horacio M. Pastawski , Gonzalo A. Alvarez

We investigate the finite-frequency thermal transport through a quantum dot subject to strong interactions, by providing an exact, nonperturbative formalism that allows us to carry out a systematic analysis of the thermopower at any…

Mesoscale and Nanoscale Physics · Physics 2014-01-28 Razvan Chirla , Catalin Pascu Moca

Computer simulations of the Ising model exhibit white noise if thermal fluctuations are governed by Boltzmann's factor alone; whereas we find that the same model exhibits 1/f noise if Boltzmann's factor is extended to include local…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 Ralph V. Chamberlin , Derek M. Nasir

The work fluctuation theorem (FT) is a symmetry connecting the moment generating functions (MGFs) of the work extracted in a given process and in its time-reversed counterpart. We show that, equivalently, the FT for work in isolated quantum…

Quantum Physics · Physics 2023-11-29 Vasco Cavina , Sadeq S. Kadijani , Massimiliano Esposito , Thomas Schmidt

The calculation of work distributions in a quantum many-body system is of significant importance and also of formidable difficulty in the field of nonequilibrium quantum statistical mechanics. To solve this problem, inspired by…

Statistical Mechanics · Physics 2020-07-01 Zhaoyu Fei , H. T. Quan

We develop a low-energy nonequilibrium field theory for weakly interacting quantum dots. The theory is based on the Keldysh field integral in the spin channel of the quantum dot described by the single impurity Anderson Hamiltonian. The…

Mesoscale and Nanoscale Physics · Physics 2012-05-14 Sergey Smirnov , Milena Grifoni

We consider tunneling of spinless electrons from a single channel emitter into an empty collector through an interacting resonant level of the quantum dot (QD). When all Coulomb screening of sudden charge variations of the dot during the…

Strongly Correlated Electrons · Physics 2019-05-22 V. V. Ponomarenko , I. A. Larkin

We compute the quantum correlation (quantum discord (QD)) and the entanglement (EoF) between nearest neighbor qubits (spin-1/2) in an infinite chain described by the Heisenberg model (XXZ Hamiltonian) at finite temperatures. The chain is in…

Quantum Physics · Physics 2015-05-19 T. Werlang , C. Trippe , G. A. P. Ribeiro , Gustavo Rigolin

We consider an "impurity" with a spin degree of freedom coupled to a finite reservoir of non-interacting electrons, a system which may be realized by either a true impurity in a metallic nano-particle or a small quantum dot coupled to a…

Mesoscale and Nanoscale Physics · Physics 2009-08-06 R. K. Kaul , D. Ullmo , G. Zarand , S. Chandrasekharan , H. U. Baranger

We study non-equilibrium (NE) fluctuation-dissipation (FD) relations in the context of quantum thermoelectric transport through a two-terminal nanodevice, in the steady-state and with interaction. The FD relations for the one- and…

Mesoscale and Nanoscale Physics · Physics 2013-05-23 H. Ness , L. K. Dash

We study the frequency-dependent noise of a suspended carbon nanotube quantum dot nanoelectromechanical resonator induced by electron-vibration coupling. Using a rigorous Keldysh diagrammatic technique, we establish a formal framework…

Mesoscale and Nanoscale Physics · Physics 2024-12-10 Dong E. Liu , Alex Levchenko

We calculate the radiation noise level associated with the spontaneous emission of a coherently driven medium. The significant field-induced modification of relation between the noise power and damping constant in a thermal reservoir is…

Quantum Physics · Physics 2016-04-13 Maria Erukhimova , Mikhail Tokman

Phonon-phonon interaction is systematically studied by nonequilibrium Green's function (NEGF) formulism in momentum space at finite temperatures. Within the quasi-particle approximation, phonon frequency shift and lifetime are obtained from…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Yong Xu , Jian-Sheng Wang , Wenhui Duan , Bing-Lin Gu , Baowen Li

Building on the many existing algorithms for calculating the DC transport properties of quantum tight-binding models, we develop a systematic approach that expresses finite frequency observables in terms of the stationary Green's function…

Mesoscale and Nanoscale Physics · Physics 2013-02-15 Oleksii Shevtsov , Xavier Waintal

We present a method, based on the Keldysh formalism, for deriving stochastic master equations that describe the non-Markovian dynamics of a quantum system coupled to a Gaussian environment. This approach yields a compact expression for the…

Quantum Physics · Physics 2026-01-21 Vasco Cavina , Antonio D'Abbruzzo , Vittorio Giovannetti

An exact expression is derived for the electron Green function in two-channel Kondo models with one and two impurities, describing the crossover from non-Fermi liquid (NFL) behavior at intermediate temperatures to standard Fermi liquid (FL)…

Strongly Correlated Electrons · Physics 2012-06-19 Andrew K. Mitchell , Eran Sela

The transport properties of a simple model for a finite level structure (a molecule or a dot) connected to metal electrodes in an alternating current scanning tunneling microscope (AC-STM) configuration is studied. The finite level…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 R. Guyon , T. Jonckheere , V. Mujica , A. Crepieux , T. Martin

We review how unitarity and stationarity in the Schwinger-Keldysh formalism naturally lead to a (quantum) generalized fluctuation-dissipation relation (gFDR) that works beyond thermal equilibrium. Non-Gaussian loop corrections are also…

Statistical Mechanics · Physics 2023-09-04 Xinyi Chen-Lin

In this paper, the cross section for the Compton scattering process at finite temperature is calculated. Temperature effects are introduced using the Thermofield Dynamics (TFD) formalism. It is a real-time finite temperature quantum field…

High Energy Physics - Theory · Physics 2023-02-01 D. S. Cabral , A. F. Santos