Nonlocal Andreev reflection, fractional charge and current-phase relation in topological bilayer exciton condensate junctions

Abstract

We study Andreev reflection and Josephson currents in topological bilayer exciton condensates (TEC). These systems can create 100% spin entangled nonlocal currents with high amplitudes due to perfect nonlocal Andreev reflection. This Andreev reflection process can be gate tuned from a regime of purely retro reflection to purely specular reflection. We have studied the bound states in TEC-TI-TEC Josephson junctions and find a gapless dispersion for perpendicular incidence. The presence of a sharp transition in the supercurrent-phase relationship when the system is in equilibrium is a signature of fractional charge, which can be further revealed in ac measurements faster than relaxation processes via Landau-Zener processes.

arXiv commentSubmitted to Physical Review B

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Cited by in corpus (5)

• Nonlocal transistor based on pure crossed Andreev reflection in a EuO-graphene/superconductor hybrid structure
• Andreev reflection at the edge of a two-dimentional semimetal
• Manipulation of Cooper pair entanglement in hybrid topological Josephson junctions
• Odd-frequency superconductivity induced in topological insulators with and without hexagonal warping
• Interlayer current near the edge of an InAs/GaSb double quantum well in proximity with a superconductor