Néel proximity effect at antiferromagnet/superconductor interfaces

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Bobkov, G. A., Bobkova, I. V., Bobkov, A. M., Kamra, Akashdeep
Natura: Preprint
Pubblicazione: 2022
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866914119409467392
author Bobkov, G. A.
Bobkova, I. V.
Bobkov, A. M.
Kamra, Akashdeep
author_facet Bobkov, G. A.
Bobkova, I. V.
Bobkov, A. M.
Kamra, Akashdeep
contents Spin-splitting induced in a conventional superconductor weakens superconductivity by destroying spin-singlet and creating spin-triplet Cooper pairs. We demonstrate theoretically that such an effect is also caused by an adjacent compensated antiferromagnet, which yields no net spin-splitting. We find that the antiferromagnet produces Néel triplet Cooper pairs, whose pairing amplitude oscillates rapidly in space similar to the antiferromagnet's spin. The emergence of these unconventional Cooper pairs reduces the singlet pairs' amplitude, thereby lowering the superconducting critical temperature. We develop a quasiclassical Green's functions description of the system employing a two-sublattice framework. It successfully captures the rapid oscillations in the Cooper pairs' amplitude at the lattice spacing scale as well as their smooth variation on the larger coherence length scale. Employing the theoretical framework thus developed, we investigate this Néel proximity effect in a superconductor/antiferromagnet bilayer as a function of interfacial exchange, disorder, and chemical potential, finding rich physics. Our findings also offer insights into experiments which have found a larger than expected suppression of superconductivity by an adjacent antiferromagnet.
format Preprint
id arxiv_https___arxiv_org_abs_2208_03962
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Néel proximity effect at antiferromagnet/superconductor interfaces
Bobkov, G. A.
Bobkova, I. V.
Bobkov, A. M.
Kamra, Akashdeep
Superconductivity
Mesoscale and Nanoscale Physics
Spin-splitting induced in a conventional superconductor weakens superconductivity by destroying spin-singlet and creating spin-triplet Cooper pairs. We demonstrate theoretically that such an effect is also caused by an adjacent compensated antiferromagnet, which yields no net spin-splitting. We find that the antiferromagnet produces Néel triplet Cooper pairs, whose pairing amplitude oscillates rapidly in space similar to the antiferromagnet's spin. The emergence of these unconventional Cooper pairs reduces the singlet pairs' amplitude, thereby lowering the superconducting critical temperature. We develop a quasiclassical Green's functions description of the system employing a two-sublattice framework. It successfully captures the rapid oscillations in the Cooper pairs' amplitude at the lattice spacing scale as well as their smooth variation on the larger coherence length scale. Employing the theoretical framework thus developed, we investigate this Néel proximity effect in a superconductor/antiferromagnet bilayer as a function of interfacial exchange, disorder, and chemical potential, finding rich physics. Our findings also offer insights into experiments which have found a larger than expected suppression of superconductivity by an adjacent antiferromagnet.
title Néel proximity effect at antiferromagnet/superconductor interfaces
topic Superconductivity
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2208.03962