Orateurs
-
C. Strunk
-
Christoph Strunk
Christoph Strunk | Supercurrent diode effects and φ0-instabilities in syntheticRashba Josephson junctions
Christoph Strunk (Université de Regensburg-Allemagne)
We study Josephson junctions in epitaxial Al/InGaAs/InAs heterostructures. Using
reflectometry, we measure the Josephson inductance as well as DC transport properties.
We find that our junctions are in the ballistic limit, featuring a current phase relation
with near-unity transmission [1]. When applying in-plane magnetic field perpendicular to
the current, the Josephson inductance reveals the presence of non-reciprocal supercurrent
far below the superconducting transition temperature that results from magnetochiral
anisotropy. Also the transport critical current Ic displays a pronounced superconducting
diode effect [2]. As the result of a small Dresselhaus component, the orientation of the
current with respect to the lattice affects the magnetochiral anisotropy [3]. At higher
magnetic field the coefficient of magneto-chiral anisotropy changes sign. This can be
understood as an instability of the spontaneous φ0-shift, resulting from competing ground
states in the Josephson coupling energy.
[1] C. Baumgartner et al., Phys. Rev. Lett. 126, 037001 (2021).
[2] C. Baumgartner et al., Nature Nanotechnology 17, 39 (2022).
[3] C. Baumgartner et al., J. Phys. Condens. Matter 34, 154005 (2022).
