Tailoring tricolor structure of magnetic topological insulator for robust axion insulator

Abstract

Exploration of novel electromagnetic phenomena is a subject of great interest in topological quantum materials. One of the unprecedented effects to be experimentally verified is topological magnetoelectric (TME) effect originating from an unusual coupling of electric and magnetic fields in materials. A magnetic heterostructure of topological insulator (TI) hosts such an exotic magnetoelectric coupling and can be expected to realize the TME effect as an axion insulator. Here we designed a magnetic TI with tricolor structure where a non-magnetic layer of (Bi, Sb)2Te3 is sandwiched by a soft ferromagnetic Cr-doped (Bi, Sb)2Te3 and a hard ferromagnetic V-doped (Bi, Sb)2Te3. Accompanied by the quantum anomalous Hall (QAH) effect, we observe zero Hall conductivity plateaus, which are a hallmark of the axion insulator state, in a wide range of magnetic field between the coercive fields of Cr- and V-doped layers. The resistance of the axion insulator state reaches as high as 10^9 ohm, leading to a gigantic magnetoresistance ratio exceeding 10,000,000% upon the transition from the QAH state. The tricolor structure of TI may not only be an ideal arena for the topologically distinct phenomena, but also provide magnetoresistive applications for advancing dissipationless topological electronics.

16 pages, 4 figures

References in corpus (6)

• Topological Field Theory of Time-Reversal Invariant Insulators
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Titanic Magnetoresistance in WTe2
• High-precision realization of robust quantum anomalous Hall state in a hard ferromagnetic topological insulator
• Trajectory of Anomalous Hall Effect toward the Quantized State in a Ferromagnetic Topological Insulator
• Scale-Invariant Dissipationless Chiral Transport in Magnetic Topological Insulators beyond the Two-Dimensional Limit

Cited by in corpus (10)

• Large Anomalous Hall Effect in Topological Insulators with Proximitized Ferromagnetic Insulators
• Coexistence of Surface Ferromagnetism and Gapless Topological State in MnBi${}_2$Te${}_4$
• Changes of Magnetism in a Magnetic Insulator due to Proximity to a Topological Insulator
• Observation of superparamagnetism in coexistence with quantum anomalous Hall C=$\pm$1 and C=0 Chern states
• Hinged Quantum Spin-Hall Effect in Antiferromagnetic Topological Insulators
• Reversed electromagnetic Vavilov-Čerenkov radiation in naturally existing magnetoelectric media
• Current scaling of the topological quantum phase transition between a quantum anomalous Hall insulator and a trivial insulator
• Structurally and Chemically Compatible BiInSe3 Substrate for Topological Insulator Thin Films
• Optical intersubband properties of a core-shell semiconductor-topological insulator quantum dot described by $\theta$-Electrodynamics
• Strong spin-dephasing in a topological insulator - paramagnet heterostructure