| Texto completo | |
| Autor(es): |
Stone, Michael
;
Lopes, Pedro L. e S.
Número total de Autores: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | PHYSICAL REVIEW B; v. 93, n. 17, p. 12-pg., 2016-05-03. |
| Resumo | |
Motivated by an apparent paradox in [X.-L. Qi, E. Witten, and S.-C. Zhang, Phys. Rev. B 87, 134519 (2013)], we use the method of gaugedWess-Zumino-Witten functionals to construct an effective action for a Weyl fermion with a Majorana mass that arises from coupling to a charged condensate. We obtain expressions for the current induced by an external gauge field and observe that the topological part of the current is only one-third of that that might have been expected from the gauge anomaly. The anomaly is not changed by the induced mass gap, however. The topological current is supplemented by a conventional supercurrent that provides the remaining two-thirds of the anomaly once the equation of motion for the Goldstone mode is satisfied. We apply our formula for the current to resolve the apparent paradox and also to the chiral magnetic effect (CME), where it predicts a reduction of the CME current to one-third of its value for a free Weyl gas in thermal equilibrium. We attribute this reduction to a partial cancellation of the CME by a chiral vortical effect current arising from the persistent rotation of the fluid induced by the external magnetic field. (AU) | |
| Processo FAPESP: | 12/03210-3 - Em busca de uma nova definição de invariante topológico |
| Beneficiário: | Pedro Leopoldo e Silva Lopes |
| Modalidade de apoio: | Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto |
| 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 |