Unavoidability of nonclassicality loss in PT -symmetric systems

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F23%3A73620189" target="_blank" >RIV/61989592:15310/23:73620189 - isvavai.cz</a>

Výsledek na webu

<a href="https://journals.aps.org/pra/pdf/10.1103/PhysRevA.108.033512" target="_blank" >https://journals.aps.org/pra/pdf/10.1103/PhysRevA.108.033512</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevA.108.033512" target="_blank" >10.1103/PhysRevA.108.033512</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Unavoidability of nonclassicality loss in PT -symmetric systems

Popis výsledku v původním jazyce

We show that the loss of nonclassicality (including quantum entanglement) cannot be compensated by the (incoherent) amplification of PT-symmetric systems. We address this problem by manipulating the quantum fluctuating forces in the Heisenberg-Langevin approach. Specifically, we analyze the dynamics of two nonlinearly coupled oscillator modes in a PT-symmetric system. An analytical solution allows us to separate the contribution of reservoir fluctuations from the evolution of quantum statistical properties of the modes. In general, as reservoir fluctuations act constantly, the complete loss of nonclassicality and entanglement is observed for long times. To elucidate the role of reservoir fluctuations in a long-time evolution of nonclassicality and entanglement, we consider and compare the predictions from two alternative models in which no fatal long-time detrimental effects on the nonclassicality and entanglement are observed. This is so as, in the first semiclassical model, no reservoir fluctuations are considered at all. This, however, violates the fluctuation-dissipation theorem. The second, more elaborated, model obeys the fluctuation-dissipation relations as it partly involves reservoir fluctuations. However, to prevent the above long-time detrimental effects, the reservoir fluctuations have to be endowed with the nonphysical properties of a sink model. In both models, additional incorporation of the omitted reservoir fluctuations results in their physically consistent behavior. This behavior, however, predicts the gradual loss of the nonclassicality and entanglement. Thus the effects of reservoir fluctuations related to damping cannot be compensated by those related to amplification. This qualitatively differs from the influence of damping and amplification to a direct coherent dynamics of PT-symmetric systems in which their mutual interference results in a periodic behavior allowing for nonclassicality and entanglement at arbitrary times.

Název v anglickém jazyce

Unavoidability of nonclassicality loss in PT -symmetric systems

Popis výsledku anglicky

We show that the loss of nonclassicality (including quantum entanglement) cannot be compensated by the (incoherent) amplification of PT-symmetric systems. We address this problem by manipulating the quantum fluctuating forces in the Heisenberg-Langevin approach. Specifically, we analyze the dynamics of two nonlinearly coupled oscillator modes in a PT-symmetric system. An analytical solution allows us to separate the contribution of reservoir fluctuations from the evolution of quantum statistical properties of the modes. In general, as reservoir fluctuations act constantly, the complete loss of nonclassicality and entanglement is observed for long times. To elucidate the role of reservoir fluctuations in a long-time evolution of nonclassicality and entanglement, we consider and compare the predictions from two alternative models in which no fatal long-time detrimental effects on the nonclassicality and entanglement are observed. This is so as, in the first semiclassical model, no reservoir fluctuations are considered at all. This, however, violates the fluctuation-dissipation theorem. The second, more elaborated, model obeys the fluctuation-dissipation relations as it partly involves reservoir fluctuations. However, to prevent the above long-time detrimental effects, the reservoir fluctuations have to be endowed with the nonphysical properties of a sink model. In both models, additional incorporation of the omitted reservoir fluctuations results in their physically consistent behavior. This behavior, however, predicts the gradual loss of the nonclassicality and entanglement. Thus the effects of reservoir fluctuations related to damping cannot be compensated by those related to amplification. This qualitatively differs from the influence of damping and amplification to a direct coherent dynamics of PT-symmetric systems in which their mutual interference results in a periodic behavior allowing for nonclassicality and entanglement at arbitrary times.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10306 - Optics (including laser optics and quantum optics)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

PHYSICAL REVIEW A

ISSN

2469-9926

e-ISSN

2469-9934

Svazek periodika

108

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

"033512-1"-"033512-12"

Kód UT WoS článku

001126369000003

EID výsledku v databázi Scopus

2-s2.0-85171873639