Probing Different Magnetic Responses in Layered Superconductors Using Tunnel Junctions

Author: Shahar, Simon

Affiliation: The Hebrew University of Jerusalem

Type: Poster

Display Dates: 22.07.2026 - 23.07.2026

Board: WT-054

Transition metal dichalcogenide (TMD) superconductors have a non-trivial response to both in-plane and out-of-plane magnetic fields. Their extreme robustness to in-plane field, a consequence of Ising spin-orbit coupling (ISOC), makes them natural candidates for the study of exotic superconducting phenomena such as Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) and equal-spin triplet pairing phases. The out-of-plane field response received less attention. In this regime, TMD superconductors exhibit a mixed phase where flux is admitted in Abrikosov vortices, having properties that shed light on aspects of the microscopic character of the superconducting order parameter. These include anisotropy, multi-band superconductivity, the coherence length (or lengths) and the upper critical field , as well as the spectrum and geometry of the Caroli-de Gennes-Matricon (CdGM) bound states in the vortex cores.

In this talk, I will focus on the range of low magnetic field, where Meissner currents and vortex penetration affect superconductivity in comparable magnitude. I will present tunneling spectra measured on NbSe2 using all-TMD tunnel junctions, in very low out-of-plane magnetic fields. Our high resolution in both energy and field allows us to observe subtle changes in the quasiparticle spectra and apparent magnetic memory loss upon reversing the field direction. We interpret this effect as the result of the gradual shift from expulsion of flux by way of Meissner currents and its admittance as vortex penetration. I will show numerical solutions to the London equations, accounting for the specific geometry of our sample, that reproduce the measured data, reinforcing our interpretation. These results establish this kind of tunnel junction as a sensitive probe for the distribution of currents in the sample, including the subtle effect of the circulating currents around superconducting vortices far away from the junction itself.