Berry phase jumps and giant nonreciprocity in Dirac quantum dots

We predict that a strong nonreciprocity in the resonance spectra of Dirac quantum dots can be induced by the Berry phase. The nonreciprocity arises in relatively weak magnetic fields and is manifest in anomalously large field-induced splittings of quantum dot resonances which are degenerate at B=0 d...

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Detalles Bibliográficos
Main Authors: Rodriguez Nieva, Joaquin Francisco, Levitov, Leonid
Outros autores: Massachusetts Institute of Technology. Department of Physics
Formato: Artigo
Idioma:English
Publicado: American Physical Society 2017
Acceso en liña:http://hdl.handle.net/1721.1/108613
https://orcid.org/0000-0002-3023-396X
https://orcid.org/0000-0002-4268-731X
Descripción
Summary:We predict that a strong nonreciprocity in the resonance spectra of Dirac quantum dots can be induced by the Berry phase. The nonreciprocity arises in relatively weak magnetic fields and is manifest in anomalously large field-induced splittings of quantum dot resonances which are degenerate at B=0 due to time-reversal symmetry. This exotic behavior, which is governed by field-induced jumps in the Berry phase of confined electronic states, is unique to quantum dots in Dirac materials and is absent in conventional quantum dots. The effect is strong for gapless Dirac particles and can overwhelm the B-induced orbital and Zeeman splittings. A finite Dirac mass suppresses the effect. The nonreciprocity, predicted for generic two-dimensional Dirac materials, is accessible through Faraday and Kerr optical rotation measurements and scanning tunneling spectroscopy.