High-temperature quantum oscillations caused by recurring Bloch states in graphene superlattices.
Science
; 357(6347): 181-184, 2017 07 14.
Article
em En
| MEDLINE
| ID: mdl-28706067
ABSTRACT
Cyclotron motion of charge carriers in metals and semiconductors leads to Landau quantization and magneto-oscillatory behavior in their properties. Cryogenic temperatures are usually required to observe these oscillations. We show that graphene superlattices support a different type of quantum oscillation that does not rely on Landau quantization. The oscillations are extremely robust and persist well above room temperature in magnetic fields of only a few tesla. We attribute this phenomenon to repetitive changes in the electronic structure of superlattices such that charge carriers experience effectively no magnetic field at simple fractions of the flux quantum per superlattice unit cell. Our work hints at unexplored physics in Hofstadter butterfly systems at high temperatures.
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Bases de dados:
MEDLINE
Idioma:
En
Revista:
Science
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Reino Unido