Magnification of signatures of a topological phase transition by quantum zero point motion

Autor(es)

Lopes, Pedro L. e S. ; Ghaemi, Pouyan

• Tipo de documento: Artigo Científico
• Fonte: Physical Review B; v. 92, n. 6, p. 13-pg., 2015-08-24.

Resumo

We show that the zero point motion of a vortex in superconducting doped topological insulators leads to significant changes in the electronic spectrum at the topological phase transition in this system. This topological phase transition is tuned by the doping level, and the corresponding effects are manifest in the density of states at energies which are on the order of the vortex fluctuation frequency. Although the electronic energy gap in the spectrum generated by a stationary vortex is but a small fraction of the bulk superconducting gap, the vortex fluctuation frequency may be much larger. As a result, this quantum zero point motion can induce a discontinuous change in the spectral features of the system at the topological vortex phase transition to energies which are well within the resolution of scanning tunneling microscopy. This discontinuous change is exclusive to superconducting systems in which we have a topological phase transition. Moreover, the phenomena studied in this paper present effects of Magnus forces on the vortex spectrum which are not present in the ordinary s-wave superconductors. Finally, we demonstrate explicitly that the vortex in this system is equivalent to a Kitaev chain. This allows for the mapping of the vortex fluctuating scenario in three dimensions into similar one-dimensional situations in which one may search for other novel signatures of topological phase transitions. (AU)

• Processo FAPESP: 09/18336-0 - Partículas relativísticas e excitações similares em matéria condensada
• Beneficiário: Pedro Leopoldo e Silva Lopes
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto