Ferroelectric switching of quantum anomalous Hall effects in MnBi2Te4 films

TL;DR

The work addresses electrically controlling topological states in ferroelectric-topological 2D heterostructures by coupling ferroelectric polarization to band topology. It employs first-principles density functional theory with Hubbard $U$ and van der Waals corrections, plus WannierTools, to study a MBT 4-SL ABCB slab interfaced with a monolayer In$_2$Te$_3$, identifying polarization-induced band inversion at $\Gamma$ that switches the Chern number between $C=1$ (QAH) and $C=0$ (trivial). Layer-resolved anomalous Hall conductivity shows the MBT layers primarily host the AHC, while polarization reversal reshapes the real-space AHC distribution and orbital hybridization at the interface. The results demonstrate ferroelectric-controlled QAH behavior in MBT/In$_2$Te$_3$ and suggest pathways for non-volatile, reconfigurable topological memory devices, with potential generalization to other ferroelectrics and MBT-family materials via electric-field switching.

Abstract

The integration of ferroelectric and topological materials offers a promising avenue for advancing the development of quantum material devices. In this work, we explore the strong coupling between topological states and ferroelectricity in the heterostructure formed by interfacing MnBi2Te4 (MBT) thin films and monolayer In2Te3. Our first-principles calculations demonstrate that the polarization direction in In2Te3 can strongly alter electronic band structures in the MBT/In2Te3 heterostructure, and even induces a topological phase transition between quantum anomalous Hall (C = 1) and trivial (C = 0) insulating states, originating from the change of band order induced by the switch of out-of-plane polarization. Our work highlights the promising potential of ferroelectric-topological heterostructures in aiding the development of reconfigurable quantum devices, and creating new possibilities for progress in advanced microelectronic and spintronic systems

Figures (4)

• Figure 1: Schematic diagrams of topological phase transition induced by electric field and ferroelectric polarization. (a) The "on" and "off" states induced by external electric field. (b) The "up" and "down" states with opposite ferroelectric polarization. (c) Schematic diagrams of bulk and edge states of quantum anomalous Hall insulating and trivial insulators. (d) The response of polarization versus external electric field, where binary states are manipulated by electric field and ferroelectric polarization.
• Figure 2: (a) Typical MnBi$_2$Te$_4$ (MBT)-ABCB/In$_2$Te$_3$ heterostructures with distinct stacking patterns, such as AB-AP-$o$, AC-AP-$i$, AB-P-$o$ and AC-P-$i$, where the relative stacking between MBT and In$_2$Te$_3$ is denoted by "AB" and "AC", the relative stacking direction is denoted by parallel ("P") and antiparallel ("AP"), and the polarization of In$_2$Te$_3$ is denoted by $i$ (inwards) and $o$ (outwards). (b) Local potential in monolayer In$_2$Te$_3$ with polarization aligning outwards and MBT 4-SL ABCB, with reference to the Fermi level.(c) Local potential in the MBT-ABCB/In$_2$Te$_3$ heterostructures with $i$ and $o$ polarization, with reference to the Fermi level.
• Figure 3: Electronic and topological properties of MBT/In$_2$Te$_3$ heterostructure with polarization inwards and outwards, denoted by AC-AP-$i$ and AC-AP-$o$. (a) and (b) Electronic band structures along high-symmetry lines and energy contours of valence and conduction bands in the AC-AP-$o$ and AC-AP-$i$ heterostructure, with the projected band structures shown in the inset, where red and blue colors denote the contribution of In$_2$Te$_3$ and MBT ABCB 4-SL slab. (c) and (d) The evolution of Wannier charge centers (WCCs) and anomalous Hall conductivity in the AC-AP-$o$ and AC-AP-$i$ case. (e) and (f) Momentum-resolved Berry curvature ($\Omega_z$) within the zoomed Brillouin zone around $\Gamma$.
• Figure 4: Layer-resolved anomalous Hall conductivity (AHC) as a function of chemical potential in MBT 4SL thin films and MBT/In$_2$Te$_3$ heterostructures, where each MBT SL and In$_2$Te$_3$ are denoted by different colors. (a and b) Layer-resolved AHC in MBT ABCA- and ABCB-stacking thin film. (c and d) Layer-resolved AHC in MBT/In$_2$Te$_3$ heterostructure with polarization inwards and outwards.