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arXiv · 2109.01061

Superconducting spintronic tunnel diode

E. Strambini·M. Spies·N. Ligato·S. Ilic·M. Rouco·C. G. Orellana·M. Ilyn·C. Rogero·F. S. Bergeret·J. S. Moodera·P. Virtanen·T. T. Heikkilä·F. Giazotto
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Abstract

Diodes are key elements for electronics, optics, and detection. The search for a material combination providing the best performances for the required application is continuously ongoing. Here, we present a superconducting spintronic tunnel diode based on the strong spin filtering and splitting generated by an EuS thin film between a superconducting Al and a normal metal Cu layer. The Cu/EuS/Al tunnel junction achieves a large rectification (up to $\sim40$\%) already for a small voltage bias ($\sim 200$ $\mu$V) 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 of the barrier and describe the quasi-ideal Schottky-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.

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E. Strambini, M. Spies, N. Ligato, S. Ilic, M. Rouco, C. G. Orellana, M. Ilyn, C. Rogero, F. S. Bergeret, J. S. Moodera, P. Virtanen, T. T. Heikkilä, F. Giazotto. 2021-09-02. Superconducting spintronic tunnel diode. https://doi.org/10.1038/s41467-022-29990-2

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