Abstract
In two-dimensional layered quantum materials, the stacking order of the layers determines both the crystalline symmetry and electronic properties such as the Berry curvature, topology and electron correlation1–4. Electrical stimuli can influence quasiparticle interactions and the free-energy landscape5,6, making it possible to dynamically modify the stacking order and reveal hidden structures that host different quantum properties. Here, we demonstrate electrically driven stacking transitions that can be applied to design non-volatile memory based on Berry curvature in few-layer WTe2. The interplay of out-of-plane electric fields and electrostatic doping controls in-plane interlayer sliding and creates multiple polar and centrosymmetric stacking orders. In situ nonlinear Hall transport reveals that such stacking rearrangements result in a layer-parity-selective Berry curvature memory in momentum space, where the sign reversal of the Berry curvature and its dipole only occurs in odd-layer crystals. Our findings open an avenue towards exploring coupling between topology, electron correlations and ferroelectricity in hidden stacking orders and demonstrate a new low-energy-cost, electrically controlled topological memory in the atomically thin limit.
Original language | English (US) |
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Pages (from-to) | 1028-1034 |
Number of pages | 7 |
Journal | Nature Physics |
Volume | 16 |
Issue number | 10 |
DOIs | |
State | Published - Jun 29 2020 |
Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2022-06-14Acknowledged KAUST grant number(s): OSR-2016-CRG5-2996
Acknowledgements: This work is supported by the US Department of Energy (DOE), Office of Basic Energy Sciences, Materials Sciences and Engineering Division, under contract number DE-AC02-76SF00515 (J.X., E.J.S., C.M.N., P.M., C.D.P., T.P.D., A.M.L.). E.J.S. acknowledges additional support from Stanford GLAM Postdoctoral Fellowship Program. C.M.N. acknowledges additional support from the National Science Foundation (NSF) through a Graduate Research Fellowship (DGE-114747). H.W. and X.Q. acknowledge support by the NSF under award number DMR-1753054. J.X., A.M.L. and C.D.P. acknowledge support for theory calculations through the Center for Non-Perturbative Studies of Functional Materials. Y.W., S.W. and X.Z. acknowledge support from the US DOE, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, within the van der Waals Heterostructures Program (KCWF16) under contract no. DE-AC02-05-CH11231 for electrical transport measurement, and from King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research award OSR-2016-CRG5-2996 for device design and fabrication. First-principles electronic structure and Berry curvature calculations by H.W. and X.Q. were conducted with the advanced computing resources provided by Texas A&M High Performance Research Computing. Part of this work was performed at the Stanford Nano Shared Facilities (SNSF)/Stanford Nanofabrication Facility (SNF), supported by the NSF under award ECCS-1542152.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.