Magnetic anisotropy reversal driven by structural symmetry-breaking in monolayer α-RuCl3

Bowen Yang; Yin Min Goh; Suk Hyun Sung; Gaihua Ye; Sananda Biswas; David A S Kaib; Ramesh Dhakal; Shaohua Yan; Chenghe Li; Shengwei Jiang; Fangchu Chen; Hechang Lei; Rui He; Roser Valentí; Stephen M Winter; Robert Hovden; Adam W Tsen

doi:10.1038/s41563-022-01401-3

Magnetic anisotropy reversal driven by structural symmetry-breaking in monolayer α-RuCl₃

Nat Mater. 2023 Jan;22(1):50-57. doi: 10.1038/s41563-022-01401-3. Epub 2022 Nov 17.

Authors

Bowen Yang^{1

2}, Yin Min Goh³, Suk Hyun Sung⁴, Gaihua Ye⁵, Sananda Biswas⁶, David A S Kaib⁶, Ramesh Dhakal⁷, Shaohua Yan⁸, Chenghe Li⁸, Shengwei Jiang^{9

10}, Fangchu Chen^{1

2}, Hechang Lei⁸, Rui He⁵, Roser Valentí⁶, Stephen M Winter¹¹, Robert Hovden^{12

13}, Adam W Tsen^{14

15}

Affiliations

¹ Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, Canada.
² Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, Canada.
³ Department of Physics, University of Michigan, Ann Arbor, MI, USA.
⁴ Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, USA.
⁵ Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX, USA.
⁶ Institut für Theoretische Physik, Goethe-Universität Frankfurt, Frankfurt am Main, Germany.
⁷ Department of Physics and Center for Functional Materials, Wake Forest University, Winston-Salem, NC, USA.
⁸ Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, China.
⁹ Department of Physics, Cornell University, Ithaca, NY, USA.
¹⁰ Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China.
¹¹ Department of Physics and Center for Functional Materials, Wake Forest University, Winston-Salem, NC, USA. winters@wfu.edu.
¹² Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, USA. hovden@umich.edu.
¹³ Applied Physics Program, University of Michigan, Ann Arbor, MI, USA. hovden@umich.edu.
¹⁴ Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, Canada. awtsen@uwaterloo.ca.
¹⁵ Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada. awtsen@uwaterloo.ca.

PMID: 36396963
DOI: 10.1038/s41563-022-01401-3

Abstract

Layered α-RuCl₃ is a promising material to potentially realize the long-sought Kitaev quantum spin liquid with fractionalized excitations. While evidence of this state has been reported under a modest in-plane magnetic field, such behaviour is largely inconsistent with theoretical expectations of spin liquid phases emerging only in out-of-plane fields. These predicted field-induced states have been largely out of reach due to the strong easy-plane anisotropy of bulk crystals, however. We use a combination of tunnelling spectroscopy, magnetotransport, electron diffraction and ab initio calculations to study the layer-dependent magnons, magnetic anisotropy, structure and exchange coupling in atomically thin samples. Due to picoscale distortions, the sign of the average off-diagonal exchange changes in monolayer α-RuCl₃, leading to a reversal of spin anisotropy to easy-axis anisotropy, while the Kitaev interaction is concomitantly enhanced. Our work opens the door to the possible exploration of Kitaev physics in the true two-dimensional limit.

Publication types

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

MeSH terms

Anisotropy
Electrons*
Magnetic Fields*