SPICE Workshop on Hybrid Correlated States and Dynamics in Quantum Materials, May 14th - 16th 2024
Stefan Ilic
Spin-split superconductors exhibit an electron-hole asymmetric spin-resolved density of states, but the symmetry is restored upon averaging over spin. On the other hand, asymmetry appears again in tunneling junctions of spin-split superconductors with a spin-polarized barrier. This fact leads to a particularly strong thermoelectric effect in superconductor/ferromagnet structures [1]. In this talk I will present another important effect stemming from the electron-hole asymmetry: current rectification [2,3,4]. I will discuss the charge transport in spin-polarized tunnel junctions of a normal metal and a spin-split superconductor with AC and DC voltage bias. In the DC case, the I-V curve is not fully antisymmetric and has a voltage-symmetric component due to spin polarization. This translates to the existence of a rectified current in the AC case, which is proportional to the spin polarization of the junction and strongly depends on the frequency of the applied bias. I will discuss possible applications of the rectification effect, including a diode for superconducting electronics and radiation detectors.
[1] Ozaeta, Virtanen, Bergeret and Heikkilä, Phys. Rev. Lett. 112 (2014)[2] Strambini, Spies, Ligato, Ilić et al, Nat. Commun. 13 (2022)
[3] Ilić, Virtanen, Heikkilä and Bergeret, Phys. Rev. Appl. 17 (2022)
[4] Geng, Hijano, Ilić, Ilyn et al, Supercond. Sci. Technol. 36 (2023)