Dephasing-enabled triplet Andreev conductance
Abstract
We study the conductance of normal-superconducting quantum dots with strong spin-orbit scattering coupled to a source reservoir using a single-mode spin-filtering quantum-point contact. The choice of the system is guided by the aim to study triplet Andreev reflection without relying on half-metallic materials with specific interface properties. Focusing on the zero-temperature, zero-bias regime, we show how dephasing due to the presence of a voltage probe enables the conductance, which vanishes in the quantum limit, to take nonzero values. Concentrating on chaotic quantum dots, we obtain the full distribution of the conductance as a function of the dephasing rate. As dephasing gradually lifts the conductance from zero, the dependence of the conductance fluctuations on the dephasing rate is nonmonotonic. This is in contrast to chaotic quantum dots in usual transport situations, where dephasing monotonically suppresses the conductance fluctuations.
- Publication:
-
Physical Review B
- Pub Date:
- June 2009
- DOI:
- 10.1103/PhysRevB.79.245315
- arXiv:
- arXiv:0903.2190
- Bibcode:
- 2009PhRvB..79x5315B
- Keywords:
-
- 73.63.Kv;
- 74.45.+c;
- 85.75.-d;
- 03.65.Yz;
- Quantum dots;
- Proximity effects;
- Andreev effect;
- SN and SNS junctions;
- Magnetoelectronics;
- spintronics: devices exploiting spin polarized transport or integrated magnetic fields;
- Decoherence;
- open systems;
- quantum statistical methods;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- 6 pages, 3 figures