Andreev tunneling, Coulomb blockade, and resonant transport of nonlocal spin-entangled electrons
By P. Recher, E. Sukhorukov, Daniel Loss. 2000
325 citations recorded by the source corpus.
We propose and analyze a spin-entangler for electrons based on an s-wave superconductor coupled to two quantum dots, each of which is coupled to normal Fermi leads. We show that in the presence of a voltage bias and in the Coulomb blockade regime two correlated electrons provided by the Andreev process can coherently tunnel from the superconductor via different dots into different leads. The spin singlet coming from the Cooper pair remains preserved in this process, and the setup provides a source of mobile and nonlocal spin-entangled electrons. The transport current is calculated and shown to be dominated by a two-particle Breit-Wigner resonance that allows the injection of two spin-entangled electrons into different leads at exactly the same orbital energy, which is a crucial requirement for the detection of spin entanglement via noise measurements. The coherent tunneling of both electrons into the same lead is suppressed by the on-site Coulomb repulsion and/or the superconducting gap, while the tunneling into different leads is suppressed through the initial separation of the tunneling electrons. In the regime of interest the particle-hole excitations of the leads are shown to be negligible. The Aharonov-Bohm oscillations in the current are shown to contain single- and two-electron periods with amplitudes that both vanish with increasing Coulomb repulsion albeit differently fast.
Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics, Condensed Matter Physics
View Paper: https://www.semanticscholar.org/paper/a804c5955e15c2ded742ab2e434d0e82f1d76e58
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Atomic and Molecular Physics, and Optics
In Condensed Matter Physics
Citations in the corpus
- Josephson and Andreev transport through quantum dots (2011, background): “Double dots coupled to several normal and superconducting leads are receiving recently considerable attention in connection to the possibility of producing nonlocal entangled electrons from the splitting of Cooper pairs (Herrmann et al., 2010; Hofstetter et al., 2009; Recher et al., 2001).”
- Quantum computers (2010, unknown): “A key example of this is the use of superconducting transmission line cavities and resonators for qubits other than those based on Josephson junctions, such as ions 91 , polar molecules 92 and quantum dots 93 .”
- Andreev bound states in supercurrent-carrying carbon nanotubes revealed (2010, unknown): “This is relevant for conventional applications (e.g. superconducting or normal transistors, SQUIDs [3]) and quantum information processing (e.g. entangled electron pairs generation [6, 7], ABS-based qubits [8] ).”