Cooper pair splitting in a nanoSQUID geometry at high transparency

Abstract

We describe a Josephson device composed of two superconductors separated by two interacting quantum dots in parallel, as a probe for Cooper pair splitting. In addition to sequential tunneling of electrons through each dot, an additional transport channel exists in this system: crossed Andreev reflection, where a Cooper pair from the source is split between the two dots and recombined in the drain superconductor. Unlike non-equilibrium scenarios for Cooper pair splitting which involves superconducting/normal metal "forks", our proposal relies on an Aharonov-Bohm measurement of the DC Josephson current when a flux is inserted between the two dots. We provide a path integral approach to treat arbitrary transparencies, and we explore all contributions for the individual phases ($0$ or $\pi$) of the quantum dots. We propose a definition of the Cooper pair splitting efficiency for arbitrary transparencies, which allows us to find the phase associations which favor the crossed Andreev process. Possible applications to experiments using nanowires as quantum dots are discussed.

12 pages, 13 figures

References in corpus (11)

• Free-Space distribution of entanglement and single photons over 144 km
• Supercurrent reversal in quantum dots
• Evidence for crossed Andreev reflection in superconductor-ferromagnet hybrid structures
• Near-unity Cooper pair splitting efficiency
• Sign of the crossed conductances at a FSF double interface
• Current and noise correlations in a double dot Cooper pair beam splitter
• Crossed Andreev reflection at ferromagnetic domain walls
• Shot noise and Coulomb effects on non-local electron transport in normal-superconducting-normal heterostructures
• Proposal for the observation of nonlocal multipair production: the biSQUID
• Crossed conductance in FSF double junctions: role of out-of-equilibrium populations
• Non local Andreev reflection in a carbon nanotube superconducting quantum interference device

Cited by in corpus (7)

• Signatures of nonlocal Cooper-pair transport and of a singlet-triplet transition in the critical current of a double-quantum-dot Josephson junction
• Crossed Andreev Reflection in InSb Flake Josephson Junctions
• Theory of non-equilibrium noise in general multi-terminal superconducting hydrid devices: application to multiple Cooper pair resonances
• Gate tunable parallel double quantum dot in InAs double-nanowire junctions
• Aharonov-Bohm and Aharonov-Casher effects in double quantum dot Josephson junction
• Cooper pair splitting in diffusive magnetic SQUIDs
• Cooper pair splitting in ballistic ferromagnetic SQUIDs