Quantum dot attached to superconducting leads: Relation between symmetric and asymmetric coupling

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F17%3A10362636" target="_blank" >RIV/00216208:11320/17:10362636 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1103/PhysRevB.95.195114" target="_blank" >http://dx.doi.org/10.1103/PhysRevB.95.195114</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.95.195114" target="_blank" >10.1103/PhysRevB.95.195114</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Quantum dot attached to superconducting leads: Relation between symmetric and asymmetric coupling

Popis výsledku v původním jazyce

We study the Anderson single-level quantum dot attached to two BCS superconducting leads with the same gap size. We reveal that a system with asymmetric tunnel coupling to the leads (Gamma(L) not equal Gamma(R)) can be related to the symmetric system with the same net coupling strength Gamma=Gamma(L) + Gamma(R). Surprisingly, it is the symmetric case which is the most general, meaning that all physical quantities in the case of asymmetric coupling are fully determined by the symmetric ones. We give ready-to-use conversion formulas for the 0-pi phase transition boundary, on-dot quantities, and the Josephson current and illustrate them on the NRG results of Oguri, Tanaka and Bauer [Phys. Rev. B 87, 075432 (2013)] for the three-terminal setup. We apply our theory to the recent 0-p transition measurement of Delagrange et al. [Phys. Rev. B 93, 195437 (2016)] and determine the asymmetry of the experimental setup from the measured transition width. Finally, we establish that the widely assumed Kondo &quot;universality&quot; of physical quantities depending only on the ratio of the Kondo temperature and the superconducting gap T-K/Delta cannot hold for asymmetric junctions.

Název v anglickém jazyce

Quantum dot attached to superconducting leads: Relation between symmetric and asymmetric coupling

Popis výsledku anglicky

We study the Anderson single-level quantum dot attached to two BCS superconducting leads with the same gap size. We reveal that a system with asymmetric tunnel coupling to the leads (Gamma(L) not equal Gamma(R)) can be related to the symmetric system with the same net coupling strength Gamma=Gamma(L) + Gamma(R). Surprisingly, it is the symmetric case which is the most general, meaning that all physical quantities in the case of asymmetric coupling are fully determined by the symmetric ones. We give ready-to-use conversion formulas for the 0-pi phase transition boundary, on-dot quantities, and the Josephson current and illustrate them on the NRG results of Oguri, Tanaka and Bauer [Phys. Rev. B 87, 075432 (2013)] for the three-terminal setup. We apply our theory to the recent 0-p transition measurement of Delagrange et al. [Phys. Rev. B 93, 195437 (2016)] and determine the asymmetry of the experimental setup from the measured transition width. Finally, we establish that the widely assumed Kondo &quot;universality&quot; of physical quantities depending only on the ratio of the Kondo temperature and the superconducting gap T-K/Delta cannot hold for asymmetric junctions.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

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

Projekt

<a href="/cs/project/GA16-19640S" target="_blank" >GA16-19640S: Vibrační efekty v nerovnovážném elektronovém transportu přes nanosystémy</a><br>

Návaznosti

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

Rok uplatnění

2017

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

—

Svazek periodika

95

Číslo periodika v rámci svazku

19

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

—

Kód UT WoS článku

000401229000005

EID výsledku v databázi Scopus

2-s2.0-85023627284