Andreev quantum dot with several conducting channels

Abstract

We study an Andreev quantum dot, that is a quantum dot inserted in a superconducting ring, with several levels or conducting channels. We analyze the degeneracy of the ground state as a function of the phase difference and of the gate voltage and find its dependence on the Coulomb interaction within and between channels. We compute a (non integer) charge of the dot region and Josephson current. The charge-to-phase and current-to-gate voltage sensitivities are studied. We find that, even in the presence of Coulomb interaction between the channels, the sensitivity increases with the number of channels, although it does not scale linearly as in the case with no interactions. The Andreev quantum dot may therefore be used as a sensitive detector of magnetic flux or as a Josephson transistor.

13 pages, 10 figures, minor corrections

References in corpus (8)

• Supercurrent reversal in quantum dots
• Quantum supercurrent transistors in carbon nanotubes
• Evidence for crossed Andreev reflection in superconductor-ferromagnet hybrid structures
• Josephson and Andreev transport through quantum dots
• Phonon Squeezing in a Superconducting Molecular Transistor
• Josephson-current induced conformational switching of a molecular quantum dot
• Continuously Tunable Charge in Andreev Quantum Dots
• Nanomechanical effects in an Andreev quantum dot

Cited by in corpus (5)

• Crossed Andreev reflection in spin-polarized chiral edge states due to the Meissner effect
• Magneto-electric spectroscopy of Andreev bound states in Josephson quantum dots
• Unitary limit in crossed Andreev transport
• Cooper pair splitting in a nanoSQUID geometry at high transparency
• Cross-correlations in a quantum dot Cooper pair splitter with ferromagnetic leads