Work

Singlet-doublet transitions and Josephson currents in a superconducting ring with a quantum dot

Year: 2026

Type: preprint

Abstract: We investigate the ground state properties of a superconducting ring embedded with a quantum dot (QD) by using a variational wave-function approach. A theoretical formulation for the treatment of the finite-U Anderson impurity coupled with a superconducting ring are presented. We demonstrate singlet-doublet transitions of the ground state for this system with the QD in the mixed valence regime. It is shown that the supercurrent in the superconductor ring shows oscillations with the external enclosed magnetic flux and exhibits abrupt jumps at the singlet-doublet phase transition points.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2608.30306

Authors: Ding, Guo-Hui, Ye, Fei, Dong, Bing

Institutions: Shanghai Jiao Tong University, Southern University of Science and Technology

Language: English

Topic: Quantum and electron transport phenomena

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funder: National Natural Science Foundation of China

Award: 分数交换和分数排斥统计在强关联系统中的应用研究

OpenAlex ID: W7204943239

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