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TT: Fachverband Tiefe Temperaturen
TT 20: Superconductivity: Tunnelling and Josephson Junctions
TT 20.6: Talk
Tuesday, March 28, 2023, 10:45–11:00, HSZ 103
Critical temperature of superconductor-ferromagnetic bilayers with helimagnetic metals — •Danilo Nikolic, Subrata Chakraborty, Alfredo Spuri, Elke Scheer, Angelo Di Bernardo, and Wolfgang Belzig — Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany
Motivated by recent experiments on the proximity effect in superconductor-ferromagnet structures with the helimagnetic ordering of magnetization in the latter, we present a systematic theoretical study of the critical temperature of such systems. By employing the quasiclassical Usadel approach [1], we account for two different configurations of magnetization in the ferromagnet and investigate their impact on the critical temperature (Tc) of the superconductor. Besides recovering the known results for the case of uniform magnetization [2], we find a nontrivial behavior of Tc in the case of spiral magnetization. Our theory suggests that this can be attributed to the emergence of long-range spin-triplet correlations generated in the ferromagnet [3]. Finally, our model predicts that the presence of spiral magnetization can reduce the critical temperature in the experimentally relevant range of parameters. This effect is the subject of ongoing experiments.
[1] A. I. Buzdin, Rev. Mod. Phys. 77, 935 (2005)
[2] Z. Radović et al., Phys. Rev. B 44, 759 (1991);
Ya. V. Fominov et al., Phys. Rev B 66, 014507 (2002)
[3] A. F. Volkov et al., Phys. Rev. B 73, 104412 (2006)