The diode effect induced by domain-wall superconductivity

Abstract

On the basis of the phenomenological Ginzburg-Landau model we calculate the critical current of the domain-wall superconducting channel formed in flux-coupled superconductor/ferromagnet (S/F) hybrids in the presence of the nonuniform magnetic field of the domain walls. It is shown that the current-carrying ability in such S/F systems in the domain-wall superconducting state differs for the positive and negative directions of the injected current with respect to the parity-breaking vector, which is proportional to V x M and thus determined by the local magnetization vector M(r) in the ferromagnetic substrate. We demonstrate that in such S/F systems the realization of the so-called diode effect is possible for both laterally infinite and mesoscopic structures.

Supercurrent diode effect and finite-momentum superconductors

“…Its origin is not yet fully understood and likely due to the orbital effect associated with the film thickness ( 31 ). We also note recent works showing that superconducting fluctuations enhance nonreciprocal resistance above T c ( 32 , 33 ) as well as works on nonreciprocal Josephson current across a weak link ( 34 – 42 ). Unlike these previous works, our focus is thin 2D superconductors where the orbital effect is suppressed, and our study provides a microscopic theory of intrinsic supercurrent diode effect in superconductors.…”

Doppler-scanning tunneling microscopy current imaging in superconductor-ferromagnet hybrids

“…A schematic of the current pattern is reported in Figure 4, in the absence (a) and in the presence of vortices (b), and it is consistent with the theoretical predictions based on GinzburgLandau calculations. 37 In summary, we have performed low-temperature scanning tunneling microscopy measurements on a magnetically coupled Pb/(Co-Pd) superconductor/ferromagnet system. Using the Doppler shift contribution to the quasiparticle excitation spectrum in the superconductor, we obtain direct imaging of the supercurrents in the superconductor using low temperature scanning tunneling microscopy.…”

Superconducting Diode Effect -- Fundamental Concepts, Material Aspects, and Device Prospects

“…It has also been shown that SDE in JJ [13] and conformal-mapped nanoholes [25] is well simulated by BdG [13] and time-dependent GL theories [25]. Furthermore, before even experimental demonstration of SDE in artificial devices [13,25], similar nonreciprocal effects have been recognized in several engineered systems [46][47][48][49][50][51][52][53][54][55][56], e.g., conventional JJs [46][47][48][49][50][51], domain-wall superconducting state [52], ferromagnetic JJ with a spinflipper weak-link acting as a quantized Josephson phase battery [53], and topological JJs [54][55][56].…”