Continuously Tunable Charge in Andreev Quantum Dots

Abstract

We show that a quantum dot connected via tunnel barriers to superconducting leads traps a continuously tunable and hence fractional charge. The fractional charge on the island is due to particle-hole symmetry breaking and can be tuned via a gate potential acting on the dot or via changes in the phase difference across the island. We determine the groundstate, equilibrium, and excitation charges and show how to identify these quantities in an experiment.

5 pages, 2 Postscript figures; minor corretions

References in corpus (8)

• Quantum supercurrent transistors in carbon nanotubes
• A Quantum Dot in the Kondo Regime Coupled to Superconductors
• Andreev quantum dots for spin manipulation
• The Interacting Impurity Josephson Junction: Variational Wavefunctions and Slave Boson Mean Field Theory
• Electrostatics of Vortices in Type II Superconductors
• Charge Transfer Induced Persistent Current and Capacitance Oscillations
• Supercurrents through gated superconductor-normal-metal-superconductor contacts: the Josephson-transistor
• Phonon relaxation of subgap levels in superconducting quantum point contacts

Cited by in corpus (10)

• Self-consistent description of Andreev bound states in Josephson quantum dot devices
• Scattering matrix approach to the description of quantum electron transport
• Real-time diagrammatic approach to transport through interacting quantum dots with normal and superconducting leads
• Non-local Andreev transport through an interacting quantum dot
• Magneto-electric spectroscopy of Andreev bound states in Josephson quantum dots
• Unitary limit in crossed Andreev transport
• Magnetic flux detection with an Andreev Quantum Dot
• Andreev quantum dot with several conducting channels
• Nanomechanical effects in an Andreev quantum dot
• Coulomb-enhanced resonance transmission of quantum SINIS junctions