Quantum Hall effect in a bulk antiferromagnet EuMnBi2 with magnetically confined two-dimensional Dirac fermions

Hidetoshi Masuda; Hideaki Sakai; Masashi Tokunaga; Yuichi Yamasaki; Atsushi Miyake; Junichi Shiogai; Shintaro Nakamura; Satoshi Awaji; Atsushi Tsukazaki; Hironori Nakao; Youichi Murakami; Taka-hisa Arima; Yoshinori Tokura; Shintaro Ishiwata

doi:10.1126/sciadv.1501117

Quantum Hall effect in a bulk antiferromagnet EuMnBi2 with magnetically confined two-dimensional Dirac fermions

Sci Adv. 2016 Jan 29;2(1):e1501117. doi: 10.1126/sciadv.1501117. eCollection 2016 Jan.

Authors

Affiliations

¹ Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
² Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.; Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan.
³ The Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan.
⁴ Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan.; RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
⁵ Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
⁶ Condensed Matter Research Center and Photon Factory, Institute of Materials Structure Science, KEK, Tsukuba 305-0801, Japan.
⁷ RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.; Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan.
⁸ Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.; RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
⁹ Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.; PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.

Abstract

For the innovation of spintronic technologies, Dirac materials, in which low-energy excitation is described as relativistic Dirac fermions, are one of the most promising systems because of the fascinating magnetotransport associated with extremely high mobility. To incorporate Dirac fermions into spintronic applications, their quantum transport phenomena are desired to be manipulated to a large extent by magnetic order in a solid. We report a bulk half-integer quantum Hall effect in a layered antiferromagnet EuMnBi2, in which field-controllable Eu magnetic order significantly suppresses the interlayer coupling between the Bi layers with Dirac fermions. In addition to the high mobility of more than 10,000 cm(2)/V s, Landau level splittings presumably due to the lifting of spin and valley degeneracy are noticeable even in a bulk magnet. These results will pave a route to the engineering of magnetically functionalized Dirac materials.

Keywords: Berry’s phase; Bi square net; Dirac fermions; europium; layered antiferromagnet; magnetoresistance; quantum hall effect; resonant x-ray magnetic scattering; spin flop transition; spintronics.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Models, Theoretical*
Physics*