Reentrant proximity-induced superconductivity for GeTe semimetal

Fuente: arXiv
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Main Authors: Esin, V. D., Kazmin, D. Yu., Barash, Yu. S., Timonina, A. V., Kolesnikov, N. N., Deviatov, E. V.
Format: Preprint
Published: 2023
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author Esin, V. D.
Kazmin, D. Yu.
Barash, Yu. S.
Timonina, A. V.
Kolesnikov, N. N.
Deviatov, E. V.
author_facet Esin, V. D.
Kazmin, D. Yu.
Barash, Yu. S.
Timonina, A. V.
Kolesnikov, N. N.
Deviatov, E. V.
contents We experimentally investigate charge transport in In-GeTe and In-GeTe-In proximity devices, which are formed as junctions between superconducting indium leads and thick single crystal flakes of $α$-GeTe topological semimetal. We observe nonmonotonic effects of the applied external magnetic field, including reentrant superconductivity in In-GeTe-In Josephson junctions: supercurrent reappears at some finite magnetic field. For a single In-GeTe Andreev junction, the superconducting gap is partially suppressed in zero magnetic field, while the gap is increased nearly to the bulk value for some finite field before its full suppression. We discuss possible reasons for the results obtained, taking into account spin polarization of Fermi arc surface states in topological semimetal $α$-GeTe with a strong spin-orbit coupling. In particular, the zero-field surface state spin polarization partially suppresses the superconductivity, while it is recovered due to the modified spin-split surface state configuration in finite fields. As an alternative possible scenario, the transition into the Fulde-Ferrell-Larkin-Ovchinnikov state is discussed. However, the role of strong spin-orbit coupling in forming the nonmonotonic behavior has not been analyzed for heterostructures in the Fulde-Ferrell-Larkin-Ovchinnikov state, which is crucial for junctions involving GeTe topological semimetal.
format Preprint
id arxiv_https___arxiv_org_abs_2304_05971
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Reentrant proximity-induced superconductivity for GeTe semimetal
Esin, V. D.
Kazmin, D. Yu.
Barash, Yu. S.
Timonina, A. V.
Kolesnikov, N. N.
Deviatov, E. V.
Mesoscale and Nanoscale Physics
Superconductivity
We experimentally investigate charge transport in In-GeTe and In-GeTe-In proximity devices, which are formed as junctions between superconducting indium leads and thick single crystal flakes of $α$-GeTe topological semimetal. We observe nonmonotonic effects of the applied external magnetic field, including reentrant superconductivity in In-GeTe-In Josephson junctions: supercurrent reappears at some finite magnetic field. For a single In-GeTe Andreev junction, the superconducting gap is partially suppressed in zero magnetic field, while the gap is increased nearly to the bulk value for some finite field before its full suppression. We discuss possible reasons for the results obtained, taking into account spin polarization of Fermi arc surface states in topological semimetal $α$-GeTe with a strong spin-orbit coupling. In particular, the zero-field surface state spin polarization partially suppresses the superconductivity, while it is recovered due to the modified spin-split surface state configuration in finite fields. As an alternative possible scenario, the transition into the Fulde-Ferrell-Larkin-Ovchinnikov state is discussed. However, the role of strong spin-orbit coupling in forming the nonmonotonic behavior has not been analyzed for heterostructures in the Fulde-Ferrell-Larkin-Ovchinnikov state, which is crucial for junctions involving GeTe topological semimetal.
title Reentrant proximity-induced superconductivity for GeTe semimetal
topic Mesoscale and Nanoscale Physics
Superconductivity
url https://arxiv.org/abs/2304.05971