Scalable effective models for superconducting nanostructures: applications to double, triple, and quadruple quantum dots

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F25%3A00641871" target="_blank" >RIV/68378271:_____/25:00641871 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11320/25:10506124

Result on the web

<a href="https://doi.org/10.1103/mxsl-fc96" target="_blank" >https://doi.org/10.1103/mxsl-fc96</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/mxsl-fc96" target="_blank" >10.1103/mxsl-fc96</a>

Result language

angličtina

Original language name

Scalable effective models for superconducting nanostructures: applications to double, triple, and quadruple quantum dots

Original language description

We introduce a versatile and scalable framework for constructing effective models of superconducting (SC) nanostructures described by the generalized SC Anderson impurity model with multiple quantum dots and leads. Our chain expansion (ChE) method maps each SC lead onto a finite tight-binding chain with parameters obtained from Padé approximants of the tunneling self-energy. We provide an explicit algorithm for the general case as well as simple analytical expressions for the chain parameters in the wide-band and infinite-chain limits. This mapping preserves low-energy physics while enabling efficient simulations: short chains are tractable using exact diagonalization, and longer ones are handled with density matrix renormalization group methods. The approach remains reliable and computationally efficient across diverse geometries, both in and out of equilibrium. We use ChE to map the ground-state phase diagrams of double, triple, and quadruple quantum dots coupled to a single SC lead. While half-filled symmetric systems show similar overall diagrams, the particular phases differ substantially with the dot number. Here, large parameter regions are entirely missed by the widely used zero-bandwidth approximation but are captured by ChE. Away from half-filling, additional dots markedly increase diagram complexity, producing a rich variety of stable phases. These results demonstrate ChE as a fast, accurate, and systematically improvable tool for exploring complex SC nanostructures.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

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

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

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

Name of the periodical

Physical Review B

ISSN

2469-9950

e-ISSN

2469-9969

Volume of the periodical

112

Issue of the periodical within the volume

20

Country of publishing house

US - UNITED STATES

Number of pages

27

Pages from-to

205418

UT code for WoS article

001629189200005

EID of the result in the Scopus database

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