• 文献标题:   High-temperature quantum oscillations caused by recurring Bloch states in graphene superlattices
  • 文献类型:   Article
  • 作  者:   KUMAR RK, CHEN X, AUTON GH, MISHCHENKO A, BANDURIN DA, MOROZOV SV, CAO Y, KHESTANOVA E, BEN SHALOM M, KRETININ AV, NOVOSELOV KS, EAVES L, GRIGORIEVA IV, PONOMARENKO LA, FAL KO VI, GEIM AK
  • 作者关键词:  
  • 出版物名称:   SCIENCE
  • ISSN:   0036-8075 EI 1095-9203
  • 通讯作者地址:   Univ Manchester
  • 被引频次:   19
  • DOI:   10.1126/science.aal3357
  • 出版年:   2017

▎ 摘  要

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.