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 (1)

• Quantum supercurrent transistors in carbon nanotubes

Cited by in corpus (4)

• 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
• Nanomechanical effects in an Andreev quantum dot