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TT: Fachverband Tiefe Temperaturen
TT 42: Superconductivity: Tunneling and Josephson Junctions
TT 42.14: Talk
Thursday, March 20, 2025, 13:00–13:15, H32
Superconductor-Altermagnet Proximity Effect with Nonmagnetic Impurities — •Christian Wiedemann1, Danilo Nikolić2, Matthias Eschrig2, and Wolfgang Belzig1 — 1Universität Konstanz, Konstanz, Germany — 2Universität Greifswald, Greifswald, Germany
Altermagnetism is a novel magnetic phase with zero net magnetization and momentum-dependent (e.g. d-wave) spin-split Fermi surface which has been recently discovered [1]. Similarly to ferromagnets [2,3], when brought to the proximity of a superconductor (S) an altermagnet (AM) modifies the spectral properties of the former [4,5]. However, most works in the field of superconducting spintronics involving altermagnets have assumed the absence of impurities that are, however, typically unavoidable in experiments. In this talk, we address this question explicitly presenting a systematic analysis of the inverse proximity effect in an S/AM bilayer in the presence of nonmagnetic impurities. Utilizing the quasiclassical Green’s function theory, we investigate the effect of impurities on observables, e.g., the self-consistently calculated order parameter and the density of states. We observe interesting phenomena such as the gapless superconductivity and an impurity-enhanced critical temperature.
[1] L. Šmejkal et al., Phys. Rev. X 12, 040501 (2022).
[2] A. I. Buzidn, Rev. Mod. Phys. 77, 935 (2005).
[3] M. Eschrig, Rep. Prog. Phys. 78, 104501 (2015).
[4] S. Chourasia et al., arXiv:2403.10456.
[5] M. Wei et al., Phys. Rev. B 109, L201404 (2024).
Keywords: Superconducting spintronics; Altermagnetism; Proximity effect; Spectral properties; Nonmagnetic impurities