Anomalous Josephson Current in Junctions with Spin-Polarizing Quantum Point Contacts

A. A. Reynoso (1) , Gonzalo Usaj (1) , C. A. Balseiro (1) , Denis Feinberg (2) , Michel Avignon (3)

1 Centro Atómico Bariloche [Argentine]
2 NEEL - ThQC - Théorie Quantique des Circuits
3 NEEL - TMC - Théorie de la Matière Condensée

We consider a ballistic Josephson junction with a quantum point contact in a two-dimensional electron gas with Rashba spin-orbit coupling. The point contact acts as a spin filter when embedded in a circuit with normal electrodes. We show that with an in-plane external magnetic field an anomalous supercurrent appears even for zero phase difference between the superconducting electrodes. In addition, the external field induces large critical current asymmetries between the two flow directions, leading to supercurrent rectifying effects.

Mots clés: Josephson junctions; Spin-orbit interaction

Domaines: Supraconductivité [cond-mat.supr-con]

A. A. Reynoso, Gonzalo Usaj, C. A. Balseiro, Denis Feinberg, Michel Avignon. Anomalous Josephson Current in Junctions with Spin-Polarizing Quantum Point Contacts. Physical Review Letters, 2008, 101 (10), pp.107001. ⟨10.1103/PhysRevLett.101.107001⟩. ⟨hal-00997186⟩