Year: 2022
Type: article
Abstract: Cooper pairing and Coulomb repulsion are antagonists, producing distinct energy gaps in superconductors and Mott insulators. When a superconductor exchanges unpaired electrons with a quantum dot, its gap is populated by a pair of electron-hole symmetric Yu-Shiba-Rusinov excitations between doublet and singlet many-body states. The fate of these excitations in the presence of a strong Coulomb repulsion in the superconductor is unknown, but of importance in applications such as topological superconducting qubits and multi-channel impurity models. Here we couple a quantum dot to a superconducting island with a tunable Coulomb repulsion. We show that a strong Coulomb repulsion changes the singlet many-body state into a two-body state. It also breaks the electron-hole energy symmetry of the excitations, which thereby lose their Yu-Shiba-Rusinov character.
Source: Nature Communications
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $5,890
Funders: Villum Fonden, European Commission, National Research Foundation, Agence Nationale de la Recherche, Danmarks Grundforskningsfond, Novo Nordisk, Javna Agencija za Raziskovalno Dejavnost RS, Novo Nordisk Fonden, QuantERA, Sino-Danish Center, Horizon 2020 Framework Programme, H2020 European Research Council
Awards: G1671306541, G3181133312, Coulombic subgap states in superconducting quantum devices, G4020117823, G4027549692, G4081538058, G434337789, G4590236199, Topologically protected states in double nanowire superconductor hybrids, G4796948450, Screening of an electron spin by an epitaxial superconducting island in a semiconductor nanowire, G5578903600, G5965242693, G6100702905, G8068201630, Hybrid Epitaxial Materials for Novel Quantum State Detection and Manipulation, Solid state theory and statistical physics
OpenAlex ID: W4224993354