Alladi Ramakrishnan Hall

Electron transport in systems of normal metals and superconductors

Abhiram Soori

ICTS, Bangalore

Electron transport in systems of superconductors and normal metals is characterised by Andreev reflection. Andreev reflection is a scattering process that happens in a system of normal metal attached to a superconductor where electron incident from normal metal results in a reflected hole and a pair of electrons enters the superconductor as a Cooper pair. Starting from the basic underlying physics of electron transport in superconducting systems, I will introduce Andreev reflection. A closely related phenomenon - crossed Andreev reflection (cAR) happens in a quantum transport set-up consisting of two normal metals attached to a superconductor, when an electron incident from one normal metal results in a hole emerging in the other. Typically, an electron tunnelling through the superconductor from one normal metal to the other competes with cAR and masks the signature of cAR in the conductance spectrum. After a general introduction to the topic, I will discuss our recently proposed novel scheme to enhance cAR over electron tunnelling (arXiv:1603.00363), connections to relevant experiments, and direct implications of our work on the production of non-locally entangled pairs of electrons.