High-temperature quantum oscillations caused by recurring Bloch states in graphene superlattices

Krishna Kumar, Roshan and Chen, X and Auton, G. H. and Mishchenko, Artem and Bandurin, D. A. and Morozov, Sergey V. and Cao, Y and Khestanova, E. and Ben Shalom, Moshe and Kretinin, A. V. and Novoselov, K. S. and Eaves, L. and Grigorieva, I. V. and Ponomarenko, Leonid Alexandrovich and Falko, Vladimir and Geim, A. K. (2017) High-temperature quantum oscillations caused by recurring Bloch states in graphene superlattices. Science, 357 (6347). pp. 181-184. ISSN 0036-8075

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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.

Item Type:
Journal Article
Journal or Publication Title:
Science
Additional Information:
Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works http://www.sciencemag.org/about/science-licenses-journal-article-reuse This is an article distributed under the terms of the Science Journals Default License.
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1000
Subjects:
ID Code:
88304
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Deposited On:
18 Oct 2017 10:14
Refereed?:
Yes
Published?:
Published
Last Modified:
20 Sep 2020 04:26