Many-body perturbation theory for the superconducting quantum dot: Fundamental role of the magnetic field

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F21%3A00553383" target="_blank" >RIV/68378271:_____/21:00553383 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1103/PhysRevB.103.235163" target="_blank" >https://doi.org/10.1103/PhysRevB.103.235163</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.103.235163" target="_blank" >10.1103/PhysRevB.103.235163</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Many-body perturbation theory for the superconducting quantum dot: Fundamental role of the magnetic field

Popis výsledku v původním jazyce

We develop the general many-body perturbation theory for a superconducting quantum dot represented by a single-impurity Anderson model attached to superconducting leads. We build our approach on a thermodynamically consistent mean-field approximation with a two-particle self-consistency of the parquet type. The two-particle self-consistency leading to a screening of the bare interaction proves substantial for suppressing the spurious transitions of the Hartree-Fock solution. We demonstrate that the magnetic field plays a fundamental role in the extension of the perturbation theory beyond the weakly correlated 0 phase. It controls the critical behavior of the 0-pi quantum transition and lifts the degeneracy in the pi phase, where the limits to zero temperature and zero magnetic field do not commute. The response to the magnetic field is quite different in 0 and pi phases. While the magnetic susceptibility vanishes in the 0 phase it becomes divergent in the pi phase at zero temperature.

Název v anglickém jazyce

Many-body perturbation theory for the superconducting quantum dot: Fundamental role of the magnetic field

Popis výsledku anglicky

We develop the general many-body perturbation theory for a superconducting quantum dot represented by a single-impurity Anderson model attached to superconducting leads. We build our approach on a thermodynamically consistent mean-field approximation with a two-particle self-consistency of the parquet type. The two-particle self-consistency leading to a screening of the bare interaction proves substantial for suppressing the spurious transitions of the Hartree-Fock solution. We demonstrate that the magnetic field plays a fundamental role in the extension of the perturbation theory beyond the weakly correlated 0 phase. It controls the critical behavior of the 0-pi quantum transition and lifts the degeneracy in the pi phase, where the limits to zero temperature and zero magnetic field do not commute. The response to the magnetic field is quite different in 0 and pi phases. While the magnetic susceptibility vanishes in the 0 phase it becomes divergent in the pi phase at zero temperature.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

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OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Physical Review B

ISSN

2469-9950

e-ISSN

2469-9969

Svazek periodika

103

Číslo periodika v rámci svazku

23

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

18

Strana od-do

235163

Kód UT WoS článku

000668994500001

EID výsledku v databázi Scopus

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