SKM 2023 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 27: Focus Session: Unconventional Transport Phenomena in Low-Dimensional Superconducting Heterostructures
TT 27.5: Vortrag
Mittwoch, 29. März 2023, 11:30–11:45, HSZ 03
Reversal of the AC and DC supercurrent diode effect in ballistic Josephson junctions — Andreas Costa1, Christian Baumgartner1, Simon Reinhardt1, Sergei Gronin2, Geoffrey C. Gardner2, Tyler Lindemann2, Michael J. Manfra2, Denis Kochan1, Jaroslav Fabian1, •Nicola Paradiso1, and Christoph Strunk1 — 1University of Regensburg — 2Purdue University
Recent experiments [1,2] have demonstrated that the supercurrent diode effect (SDE), –i.e., a nonreciprocal supercurrent– can be obtained by applying a Zeeman field in the presence of spin-orbit coupling. The effect consists in a finite difference Δ Ic between positive Ic+ and negative |Ic−| critical current (DC SDE), and an asymmetry in the Josephson inductance as a function of current (AC SDE). In this work, we show that, at high in-plane fields, the AC and DC SDE both change sign. Based on a minimal and analytical model, we clearly identify the origin of this sign change in terms of a 0-π-like transition –an effect predicted in the literature [3] but so far never experimentally observed. Thanks to our inductance measurements we can directly link the AC SDE reversal to the modification of the CPR induced by the Zeeman field. Our results illustrate the power of the Josephson inductance as a probe of phase transitions in unconventional superconductors.
[1] Ando et al., Nature 584, 373 (2020)
[2] Baumgartner et al., Nature Nano. 17, 39, (2022)
[3] Yokoyama et al., Phys. Rev. B 89, 195407 (2014)