Busca avançada
Ano de início
Entree


Magnetic Control of Soft Chiral Phonons in PbTe

Texto completo
Autor(es):
Mostrar menos -
Baydin, Andrey ; Hernandez, Felix G. G. ; Rodriguez-Vega, Martin ; Okazaki, Anderson K. ; Tay, Fuyang ; Noe, G. Timothy ; Katayama, Ikufumi ; Takeda, Jun ; Nojiri, Hiroyuki ; Rappl, Paulo H. O. ; Abramof, Eduardo ; Fiete, Gregory A. ; Kono, Junichiro
Número total de Autores: 13
Tipo de documento: Artigo Científico
Fonte: Physical Review Letters; v. 128, n. 7, p. 6-pg., 2022-02-15.
Resumo

PbTe crystals have a soft transverse optical phonon mode in the terahertz frequency range, which is known to efficiently decay into heat-carrying acoustic phonons, resulting in anomalously low thermal conductivity. Here, we studied this phonon via polarization-dependent terahertz spectroscopy. We observed softening of this mode with decreasing temperature, indicative of incipient ferroelectricity, which we explain through a model including strong anharmonicity with a quartic displacement term. In magnetic fields up to 25 T, the phonon mode splits into two modes with opposite handedness, exhibiting circular dichroism. Their frequencies display Zeeman splitting together with an overall diamagnetic shift with increasing magnetic field. Using a group-theoretical approach, we demonstrate that these observations are the result of magnetic field-induced morphic changes in the crystal symmetries through the Lorentz force exerted on the lattice ions. Thus, our Letter reveals a novel process of controlling phonon properties in a soft ionic lattice by a strong magnetic field. (AU)

Processo FAPESP: 18/06142-5 - Rotação de Kerr/Faraday em materiais quânticos
Beneficiário:Felix Guillermo Gonzalez Hernandez
Modalidade de apoio: Auxílio à Pesquisa - Regular
Processo FAPESP: 15/16191-5 - Pesquisas em novos materiais envolvendo campos magnéticos intensos e baixas temperaturas
Beneficiário:Gennady Gusev
Modalidade de apoio: Auxílio à Pesquisa - Temático