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Related papers: Persistent current noise

200 papers

In this work, we study persistent current in a mesoscopic cylinder subjected to both longitudinal and transverse magnetic fluxes. A simple tight-binding model is used to describe the system, where all the calculations are performed exactly…

Mesoscale and Nanoscale Physics · Physics 2009-06-29 Santanu K. Maiti , F. Aeenehvand

Quantum coherences are paramount resources for applications, such as quantum-enhanced light-harvesting or quantum computing, which are fragile against environmental noise. We here derive generalized quantum master equations using…

Quantum Physics · Physics 2020-09-03 Chahan M. Kropf

Quantum fluctuations are ubiquitous in physics. Ranging from conventional examples like the harmonic oscillator to intricate theories on the origin of the universe, they alter virtually all aspects of matter -- including superconductivity,…

Materials Science · Physics 2021-01-04 Juba Bouaziz , Julen Ibañez-Azpiroz , Filipe S. M. Guimarães , Samir Lounis

We investigate the time-dependent fluctuations of the electric current injected from a reservoir with a non-equilibrium spin accumulation into a mesoscopic conductor. We show how the current noise power directly reflects the magnitude of…

Mesoscale and Nanoscale Physics · Physics 2011-08-29 Jonathan Meair , Peter Stano , Philippe Jacquod

Microscopic current fluctuations are inseparable from conductance. We give an integral account of both quantized conductance and nonequilibrium thermal noise in one-dimensional ballistic wires. Our high-current noise theory opens a very…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Frederick Green , Mukunda P Das

An expression that relates thermal current fluctuations in two terminal networks at quasi-equilibrium to their current voltage characteristics is presented. It is based upon the observation that the available thermal noise power at…

Statistical Mechanics · Physics 2011-07-19 D. Ritter

The transition between distinct phases of matter is characterized by the nature of fluctuations near the critical point. We demonstrate that noise spectroscopy can not only diagnose the presence of a phase transition, but can also determine…

Quantum Physics · Physics 2023-08-24 Francisco Machado , Eugene A. Demler , Norman Y. Yao , Shubhayu Chatterjee

We study the robustness of quantum key distribution protocols using discrete or continuous variables to the channel noise. We introduce the model of such noise based on coupling of the signal to a thermal reservoir, typical for…

Quantum Physics · Physics 2017-06-12 Mikołaj Lasota , Radim Filip , Vladyslav C. Usenko

We discuss the phase coherence properties of a mesoscopic normal ring coupled to an electric environment via Coulomb interactions. This system can be mapped onto the Caldeira-Leggett model with a flux dependent tunneling amplitude. We show…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Pascal Cedraschi , Markus Buttiker

Dissipation and the accompanying fluctuations are often seen as detrimental for quantum systems, since they are associated with fast relaxation and loss of phase coherence. However, it has been proposed that a pure state can be prepared if…

Integrating solid-state spin defects into classical electronic devices can enable new opportunities for quantum information processing that benefit from existing semiconductor technology. We show, through bias control of an isotopically…

The response of an arbitrary closed quantum system to a partially coherent electric field is investigated, with a focus on the transient coherences in the system. As a model we examine, both perturbatively and numerically, the coherences…

Quantum Physics · Physics 2014-03-05 Z. S. Sadeq , Paul Brumer

We show that specific quantum noise, acting as an open-system reservoir for non-locally entangled atoms, can serve to preserve rather than degrade joint coherence. This creates a new type of long-time control over hiding and recovery of…

Quantum Physics · Physics 2009-12-01 Muhammed Yonac , Joseph H. Eberly

We examine a stochastic noise process that has a decohering effect on the average evolution of qubits in the quantum register of the solid state quantum computer proposed by Kane. We consider the effects of this process on the single qubit…

Quantum Physics · Physics 2007-05-23 C. J. Wellard , L. C. L. Hollenberg

While dephasing noise frequently presents obstacles for quantum devices, it can become an asset in the context of a Brownian-type quantum refrigerator. Here we demonstrate a novel quantum thermal machine that leverages noise-assisted…

A general theory of thermal magnetic fluctuations near conductive materials is developed; such fluctuations are the magnetic analog of Johnson noise. For realistic experiments in quantum computing and magnetic resonance force microscopy,…

Quantum Physics · Physics 2007-05-23 J. A. Sidles , J. L. Garbini , W. M. Dougherty , S. H. Chao

Using numerical simulations we investigate dynamical quantum chaos in isolated nuclear spin systems. We determine the structure of quantum states, investigate the validity of the Curie law for magnetic susceptibility and find the spectrum…

Materials Science · Physics 2013-05-29 J. A. Ludlow , O. P. Sushkov

Realistic quantum computing is subjected to noise. A most important frontier in research of quantum computing is to implement noise-resilient quantum control over qubits. Dynamical decoupling can protect coherence of qubits. Here we…

Quantum Physics · Physics 2013-10-16 Gang-Qin Liu , Hoi Chun Po , Jiangfeng Du , Ren-Bao Liu , Xin-Yu Pan

Currents in a metallic ring with a quantum dot are studied in the framework of a Langevin equation for a magnetic flux passing through the ring. Two scenarios are considered: one in which thermal fluctuations of the dissipative part of the…

Mesoscale and Nanoscale Physics · Physics 2015-04-09 Lukasz Machura , Jerzy Łuczka

The fluctuations of electrical current provide information on the dynamics of electrons in quantum devices. Understanding the nature of these fluctuations in a quantum dot is thus a crucial step insofar as this system is the elementary…

Mesoscale and Nanoscale Physics · Physics 2018-10-08 A. Crépieux , S. Sahoo , T. Q. Duong , R. Zamoum , M. Lavagna