Институт теоретической физики им. Л.Д. Ландау РАН
L.D. Landau Institute for Theoretical Physics RAS
Research in superconductivity and beyond Gerasim Eliashberg memorial conference
August, 23-26, 2021
Zeeman-driven superconductor-insulator transition in strongly disordered MoC films. STM studies in transverse magnetic fields
Date/Time: 14:00 23-Aug-2021
The superconductor-insulator transition in a transverse magnetic field is studied in a highly disordered MoC film with the product of the Fermi momentum and the mean free path kF*l close to unity. Surprisingly, the Zeeman paramagnetic effects dominate over orbital coupling on both sides of the transition . In the superconducting state it is evidenced by a high upper critical magnetic field Bc2, by its square-root dependence on temperature, as well as by the Zeeman splitting of the quasiparticle density of states measured by scanning tunneling microscopy. At Bc2 a logarithmic anomaly in DOS is observed. This anomaly is further enhanced in an increasing magnetic field, which is explained by the Zeeman splitting of the Altshuler-Aronov DOS driving the system into a more insulating or resistive state. A spin-dependent Altshuler-Aronov correction is also needed to explain the transport behavior above Bc2.
 M. Žemlička et al., Phys. Rev. B 102 (2020), 180508(R).
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