TY - JOUR

T1 - Quantum anomalous Hall effect in two-dimensional magnetic insulator heterojunctions

AU - Pan, Jinbo

AU - Yu, Jiabin

AU - Zhang, Yan Fang

AU - Du, Shixuan

AU - Janotti, Anderson

AU - Liu, Chao Xing

AU - Yan, Qimin

N1 - Funding Information:
We thank Cui-zu Chang and Xiaodong Xu for the helpful discussion. J.P. and Q.Y. acknowledge support from the U.S. Department of Energy under Award #DESC0019275 for the design of data-driven discovery pipeline and the first-principles computational work. J.Y. and C.X.L. acknowledge the support of DOE grant (DESC0019064) for the analytical model and symmetry analysis, and the Office of Naval Research (Grant number N00014-18-1-2793), as well as Kaufman New Initiative research grant of the Pittsburgh Foundation. A.J. acknowledges support from U.S. DOE SE-SC0014388. S.X.D. thanks the International Partnership Program of Chinese Academy of Sciences, Grant number 112111KYSB20160061. It benefitted from the supercomputing resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract number DE-AC02-05CH11231.

PY - 2020/12/1

Y1 - 2020/12/1

N2 - Recent years have witnessed tremendous success in the discovery of topological states of matter. Particularly, sophisticated theoretical methods in time-reversal-invariant topological phases have been developed, leading to the comprehensive search of crystal database and the prediction of thousands of topological materials. In contrast, the discovery of magnetic topological phases that break time reversal is still limited to several exemplary materials because the coexistence of magnetism and topological electronic band structure is rare in a single compound. To overcome this challenge, we propose an alternative approach to realize the quantum anomalous Hall (QAH) effect, a typical example of magnetic topological phase, via engineering two-dimensional (2D) magnetic van der Waals heterojunctions. Instead of a single magnetic topological material, we search for the combinations of two 2D (typically trivial) magnetic insulator compounds with specific band alignment so that they can together form a type-III broken-gap heterojunction with topologically non-trivial band structure. By combining the data-driven materials search, first-principles calculations, and the symmetry-based analytical models, we identify eight type-III broken-gap heterojunctions consisting of 2D ferromagnetic insulators in the MXY compound family as a set of candidates for the QAH effect. In particular, we directly calculate the topological invariant (Chern number) and chiral edge states in the MnNF/MnNCl heterojunction with ferromagnetic stacking. This work illustrates how data-driven material science can be combined with symmetry-based physical principles to guide the search for heterojunction-based quantum materials hosting the QAH effect and other exotic quantum states in general.

AB - Recent years have witnessed tremendous success in the discovery of topological states of matter. Particularly, sophisticated theoretical methods in time-reversal-invariant topological phases have been developed, leading to the comprehensive search of crystal database and the prediction of thousands of topological materials. In contrast, the discovery of magnetic topological phases that break time reversal is still limited to several exemplary materials because the coexistence of magnetism and topological electronic band structure is rare in a single compound. To overcome this challenge, we propose an alternative approach to realize the quantum anomalous Hall (QAH) effect, a typical example of magnetic topological phase, via engineering two-dimensional (2D) magnetic van der Waals heterojunctions. Instead of a single magnetic topological material, we search for the combinations of two 2D (typically trivial) magnetic insulator compounds with specific band alignment so that they can together form a type-III broken-gap heterojunction with topologically non-trivial band structure. By combining the data-driven materials search, first-principles calculations, and the symmetry-based analytical models, we identify eight type-III broken-gap heterojunctions consisting of 2D ferromagnetic insulators in the MXY compound family as a set of candidates for the QAH effect. In particular, we directly calculate the topological invariant (Chern number) and chiral edge states in the MnNF/MnNCl heterojunction with ferromagnetic stacking. This work illustrates how data-driven material science can be combined with symmetry-based physical principles to guide the search for heterojunction-based quantum materials hosting the QAH effect and other exotic quantum states in general.

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U2 - 10.1038/s41524-020-00419-y

DO - 10.1038/s41524-020-00419-y

M3 - Article

AN - SCOPUS:85092446378

VL - 6

JO - npj Computational Materials

JF - npj Computational Materials

SN - 2057-3960

IS - 1

M1 - 152

ER -