Rational Design Principles of the Quantum Anomalous Hall Effect in Superlatticelike Magnetic Topological Insulators

Abstract

As one of paradigmatic phenomena in condensed matter physics, the quantum anomalous Hall effect (QAHE) in stoichiometric Chern insulators has drawn great interest for years. By using model Hamiltonian analysis and first-principle calculations, we establish a topological phase diagram and map on it with different two-dimensional configurations, which is taken from the recently-grown magnetic topological insulators MnBi4Te7 and MnBi6Te10 with superlattice-like stacking patterns. These configurations manifest various topological phases, including quantum spin Hall effect with and without time-reversal symmetry, as well as QAHE. We then provide design principles to trigger QAHE by tuning experimentally accessible knobs, such as slab thickness and magnetization. Our work reveals that superlattice-like magnetic topological insulators with tunable exchange interaction serve as an ideal platform to realize the long-sought QAHE in pristine compounds, paving a new avenue within the area of topological materials.

Universal gapless Dirac cone and tunable topological states in (MnBi2Te4)m(

“…S7). Regardless of the exact new state, our results indicate that the magnetic structure of the (MnBi2Te4)m(Bi2Te3)n system may be easily changed, supporting the proposal to realize various topological quantum phases via magnetic tuning [16,22].…”

“…In the meantime, the electron band dispersion of the surface states, presumably dominated by the top surface [20,21], is found to be sensitive to different stackings of the underlying MnBi2Te4 and Bi2Te3 layers. Our results suggest the high tunability of both magnetic and electronic structures of the topological surface states in (MnBi2Te4)m(Bi2Te3)n heterostructures, which is essential in realizing various novel topological states [16,22].…”

“…In the newly discovered magnetic topological insulator MnBi2Te4 [1][2][3][4][5][6][7][8], both axion insulator state and quantized anomalous Hall effect (QAHE) have been observed by tuning the magnetic structure [9][10][11]. The related (MnBi2Te4)m(Bi2Te3)n heterostructures with increased tuning knobs, are predicted to be a more versatile platform for exotic topological states [12][13][14][15][16]. Here, we report angle-resolved photoemission spectroscopy (ARPES) studies on a series of the heterostructures (MnBi2Te4, MnBi4Te7 and MnBi6Te10).…”

“…Different from the surface states in typical van der Waals topological insulators, whose band dispersions are mainly determined by the surface layer itself [20,21], the surface states in (MnBi2Te4)m(Bi2Te3)n are found to be sensitive to different stackings of the underlying MnBi2Te4 and Bi2Te3 layers. Such a behavior, when combined with the tunable magnetic structure, provides an experimental basis for the theoretical proposal to realize exotic topological states by manipulating the magnetic structure and different combinations of the two building block layers in (MnBi2Te4)m(Bi2Te3)n heterostructures [16,22].…”

Dirac Surface States in Intrinsic Magnetic Topological Insulators EuSn2As2 and Li1, Gao2, Duan3 et al. 2019Phys. Rev. X259101142View full textAdd to dashboardCite

“…In the past year, significant progress has been made in this field [16][17][18][19][20][21][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39].…”