Superconducting spintronic tunnel diode

Abstract

Diodes are key elements for electronics, optics, and detection. Their evolution towards low dissipation electronics has seen the hybridization with superconductors and the realization of supercurrent diodes with zero resistance in only one direction. Here, we present the quasi-particle counterpart, a superconducting tunnel diode with zero conductance in only one direction. The direction-selective propagation of the charge has been obtained through the broken electron-hole symmetry induced by the spin selection of the ferromagnetic tunnel barrier: a EuS thin film separating a superconducting Al and a normal metal Cu layer. The Cu/EuS/Al tunnel junction achieves a large rectification (up to ∼40%) already for a small voltage bias (∼200 μV) thanks to the small energy scale of the system: the Al superconducting gap. With the help of an analytical theoretical model we can link the maximum rectification to the spin polarization (P) of the barrier and describe the quasi-ideal Shockley-diode behavior of the junction. This cryogenic spintronic rectifier is promising for the application in highly-sensitive radiation detection for which two different configurations are evaluated. In addition, the superconducting diode may pave the way for future low-dissipation and fast superconducting electronics.

Supercurrent diode effect and magnetochiral anisotropy in few-layer NbSe2

“…There is a satisfactory understanding of the mechanisms producing nonreciprocal resistance and theory predictions successfully describe the experiments 10 , 11 . On this basis, some first applications, such as superconducting antenna rectifiers 8 or spin filtering diodes 12 , have already been proposed.…”

Non-reciprocity of vortex-limited critical current in conventional superconducting micro-bridges

“…In the presence of symmetry breaking potentials, the magnitudes of critical currents of a superconductor (SC) are unequal for the two bias polarities [1][2][3][4][5][6][7][8] . This phenomenon is called the superconducting diode effect (SDE) and may arise due to simultaneous breaking of time reversal symmetry (TRS) and inversion symmetry (IS).…”

Non-Reciprocal Supercurrents in a Field-Free Graphene Josephson Triode

“…While these studies have followed a decade-long explorations of non-reciprocal supercurrents [9][10][11][12][13][14][15][16][17][18][19], the recent interest is driven by the search of novel materials which break both the inversion and time-reversal symmetry, thereby intrinsically enabling the superconducting diode effect (SDE). Such materials have indeed been experimentally identified and investigated, ranging from metallic films and proximitized semiconductors to van der Waals heterostructures [20][21][22][23][24][25][26][27][28][29][30]. While this direction offers a probe into the symmetry properties of novel materials, the resulting devices typically have limited diode efficiency, which is defined as a ratio of supercurrent in the forward and backward directions.…”