Nonlinear relaxation phenomena in metastable condensed matter systems

Davide Valenti, Bernardo Spagnolo, Dominique Persano Adorno, Angelo Carollo, Claudio Guarcello, Luca Magazzù, Claudio Guarcello, Angelo Carollo, Bernardo Spagnolo

Risultato della ricerca: Article

27 Citazioni (Scopus)

Abstract

Nonlinear relaxation phenomena in three different systems of condensed matter are investigated. (i) First, the phase dynamics in Josephson junctions is analyzed. Specifically, a superconductor-graphene-superconductor (SGS) system exhibits quantum metastable states, and the average escape time from these metastable states in the presence of Gaussian and correlated fluctuations is calculated, accounting for variations in the the noise source intensity and the bias frequency. Moreover, the transient dynamics of a long-overlap Josephson junction (JJ) subject to thermal fluctuations and non-Gaussian noise sources is investigated. Noise induced phenomena are observed, such as the noise enhanced stability and the stochastic resonant activation. (ii) Second, the electron spin relaxation process in a n-type GaAs bulk driven by a fluctuating electric field is investigated. In particular, by using a Monte Carlo approach, we study the influence of a random telegraph noise on the spin polarized transport. Our findings show the possibility to raise the spin relaxation length by increasing the amplitude of the external fluctuations. Moreover, we find that, crucially, depending on the value of the external field strength, the electron spin depolarization length versus the noise correlation time increases up to a plateau. (iii) Finally, the stabilization of quantum metastable states by dissipation is presented. Normally, quantum fluctuations enhance the escape from metastable states in the presence of dissipation. We show that dissipation can enhance the stability of a quantum metastable system, consisting of a particle moving in a strongly asymmetric double well potential, interacting with a thermal bath. We find that the escape time from the metastable region has a nonmonotonic behavior versus the system- bath coupling and the temperature, producing a stabilizing effect.
Lingua originaleEnglish
pagine (da-a)1-26
Numero di pagine26
RivistaEntropy
Volume19
Stato di pubblicazionePublished - 2017

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metastable state
escape
dissipation
electron spin
Josephson junctions
baths
depolarization
plateaus
field strength
graphene
stabilization
activation
electric fields
temperature

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cita questo

Nonlinear relaxation phenomena in metastable condensed matter systems. / Valenti, Davide; Spagnolo, Bernardo; Persano Adorno, Dominique; Carollo, Angelo; Guarcello, Claudio; Magazzù, Luca; Guarcello, Claudio; Carollo, Angelo; Spagnolo, Bernardo.

In: Entropy, Vol. 19, 2017, pag. 1-26.

Risultato della ricerca: Article

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title = "Nonlinear relaxation phenomena in metastable condensed matter systems",
abstract = "Nonlinear relaxation phenomena in three different systems of condensed matter are investigated. (i) First, the phase dynamics in Josephson junctions is analyzed. Specifically, a superconductor-graphene-superconductor (SGS) system exhibits quantum metastable states, and the average escape time from these metastable states in the presence of Gaussian and correlated fluctuations is calculated, accounting for variations in the the noise source intensity and the bias frequency. Moreover, the transient dynamics of a long-overlap Josephson junction (JJ) subject to thermal fluctuations and non-Gaussian noise sources is investigated. Noise induced phenomena are observed, such as the noise enhanced stability and the stochastic resonant activation. (ii) Second, the electron spin relaxation process in a n-type GaAs bulk driven by a fluctuating electric field is investigated. In particular, by using a Monte Carlo approach, we study the influence of a random telegraph noise on the spin polarized transport. Our findings show the possibility to raise the spin relaxation length by increasing the amplitude of the external fluctuations. Moreover, we find that, crucially, depending on the value of the external field strength, the electron spin depolarization length versus the noise correlation time increases up to a plateau. (iii) Finally, the stabilization of quantum metastable states by dissipation is presented. Normally, quantum fluctuations enhance the escape from metastable states in the presence of dissipation. We show that dissipation can enhance the stability of a quantum metastable system, consisting of a particle moving in a strongly asymmetric double well potential, interacting with a thermal bath. We find that the escape time from the metastable region has a nonmonotonic behavior versus the system- bath coupling and the temperature, producing a stabilizing effect.",
keywords = "Josephson junction, Metastability, Noise enhanced stability, Nonequilibrium statistical mechanics and nonlinear relaxation time, Open quantum systems, Quantum noise enhanced stability, Spin polarized transport in semiconductors",
author = "Davide Valenti and Bernardo Spagnolo and {Persano Adorno}, Dominique and Angelo Carollo and Claudio Guarcello and Luca Magazz{\`u} and Claudio Guarcello and Angelo Carollo and Bernardo Spagnolo",
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journal = "Entropy",
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T1 - Nonlinear relaxation phenomena in metastable condensed matter systems

AU - Valenti, Davide

AU - Spagnolo, Bernardo

AU - Persano Adorno, Dominique

AU - Carollo, Angelo

AU - Guarcello, Claudio

AU - Magazzù, Luca

AU - Guarcello, Claudio

AU - Carollo, Angelo

AU - Spagnolo, Bernardo

PY - 2017

Y1 - 2017

N2 - Nonlinear relaxation phenomena in three different systems of condensed matter are investigated. (i) First, the phase dynamics in Josephson junctions is analyzed. Specifically, a superconductor-graphene-superconductor (SGS) system exhibits quantum metastable states, and the average escape time from these metastable states in the presence of Gaussian and correlated fluctuations is calculated, accounting for variations in the the noise source intensity and the bias frequency. Moreover, the transient dynamics of a long-overlap Josephson junction (JJ) subject to thermal fluctuations and non-Gaussian noise sources is investigated. Noise induced phenomena are observed, such as the noise enhanced stability and the stochastic resonant activation. (ii) Second, the electron spin relaxation process in a n-type GaAs bulk driven by a fluctuating electric field is investigated. In particular, by using a Monte Carlo approach, we study the influence of a random telegraph noise on the spin polarized transport. Our findings show the possibility to raise the spin relaxation length by increasing the amplitude of the external fluctuations. Moreover, we find that, crucially, depending on the value of the external field strength, the electron spin depolarization length versus the noise correlation time increases up to a plateau. (iii) Finally, the stabilization of quantum metastable states by dissipation is presented. Normally, quantum fluctuations enhance the escape from metastable states in the presence of dissipation. We show that dissipation can enhance the stability of a quantum metastable system, consisting of a particle moving in a strongly asymmetric double well potential, interacting with a thermal bath. We find that the escape time from the metastable region has a nonmonotonic behavior versus the system- bath coupling and the temperature, producing a stabilizing effect.

AB - Nonlinear relaxation phenomena in three different systems of condensed matter are investigated. (i) First, the phase dynamics in Josephson junctions is analyzed. Specifically, a superconductor-graphene-superconductor (SGS) system exhibits quantum metastable states, and the average escape time from these metastable states in the presence of Gaussian and correlated fluctuations is calculated, accounting for variations in the the noise source intensity and the bias frequency. Moreover, the transient dynamics of a long-overlap Josephson junction (JJ) subject to thermal fluctuations and non-Gaussian noise sources is investigated. Noise induced phenomena are observed, such as the noise enhanced stability and the stochastic resonant activation. (ii) Second, the electron spin relaxation process in a n-type GaAs bulk driven by a fluctuating electric field is investigated. In particular, by using a Monte Carlo approach, we study the influence of a random telegraph noise on the spin polarized transport. Our findings show the possibility to raise the spin relaxation length by increasing the amplitude of the external fluctuations. Moreover, we find that, crucially, depending on the value of the external field strength, the electron spin depolarization length versus the noise correlation time increases up to a plateau. (iii) Finally, the stabilization of quantum metastable states by dissipation is presented. Normally, quantum fluctuations enhance the escape from metastable states in the presence of dissipation. We show that dissipation can enhance the stability of a quantum metastable system, consisting of a particle moving in a strongly asymmetric double well potential, interacting with a thermal bath. We find that the escape time from the metastable region has a nonmonotonic behavior versus the system- bath coupling and the temperature, producing a stabilizing effect.

KW - Josephson junction

KW - Metastability

KW - Noise enhanced stability

KW - Nonequilibrium statistical mechanics and nonlinear relaxation time

KW - Open quantum systems

KW - Quantum noise enhanced stability

KW - Spin polarized transport in semiconductors

UR - http://hdl.handle.net/10447/224476

UR - http://www.mdpi.com/1099-4300/19/1/20/pdf

M3 - Article

VL - 19

SP - 1

EP - 26

JO - Entropy

JF - Entropy

SN - 1099-4300

ER -