Scaling of subgap excitations in a superconductor-semiconductor nanowire quantum dot
Eduardo J. H. Lee, Xiaocheng Jiang, Rok Žitko, Ramón Aguado, Charles M. Lieber, Silvano De Franceschi
DOI 10.1103/PhysRevB.95.180502 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
A quantum dot coupled to a superconducting contact provides a tunable artificial analog of a magnetic atom in a superconductor, a paradigmatic quantum impurity problem. We realize such a system with an InAs semiconductor nanowire contacted by an Al-based superconducting electrode. We use an additional normal-type contact as a weakly coupled tunnel probe to perform tunneling spectroscopy measurements of the elementary subgap excitations, known as Andreev bound states or Yu-Shiba-Rusinov states. We demonstrate that the energy of these states ζ scales with the ratio between the Kondo temperature TK and the superconducting gap Δ. ζ vanishes for TK/Δ≈0.6, denoting a quantum phase transition between the spin singlet and doublet ground states. By further leveraging the gate control over the quantum dot parameters, we determine the singlet-doublet phase boundary in the stability diagram of the system. Our experimental results show remarkable quantitative agreement with numerical renormalization group calculations.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| Al Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
Similar papers
Magnetic-field-induced transition in a quantum dot coupled to a superconductor
similarity 0.96A. García Corral et al.
Source status unknown — claims are unverified
Length-Scale Dependence of the Superconductor-to-Insulator Quantum Phase Transition in One Dimension
similarity 0.95Edmond Chow et al.
Source status unknown — claims are unverified
Efficiency of quasiparticle evacuation in superconducting devices
similarity 0.95Sukumar Rajauria et al.
Source status unknown — claims are unverified
Suppression of Cooper-pair tunneling in superconducting charge boxes in tunable electromagnetic environments
similarity 0.95Watson Kuo et al.
Source status unknown — claims are unverified
Charge transport processes in a superconducting single-electron transistor coupled to a microstrip transmission line
similarity 0.94W. Lu et al.
Source status unknown — claims are unverified
Resonant Tunneling through a Macroscopic Charge State in a Superconducting Single Electron Transistor
similarity 0.94D. V. Averin et al.
Source status unknown — claims are unverified