Trajectory of the anomalous Hall effect towards the quantized state in a ferromagnetic topological insulator

By Joe Checkelsky, R. Yoshimi, A. Tsukazaki, Kei S. Takahashi, Y. Kozuka, J. Falson, Masashi Kawasaki, Y. Tokura. Nature Physics, 2014

602 citations recorded by the source corpus.

Quantized resistivity values for 2D electron systems don’t necessarily result from an external magnetic field as in the ‘normal’ quantum Hall effect; they can arise due to a material's intrinsic ferromagnetism too—the quantum anomalous Hall effect. Experiments with a ferromagnetic topological insulator now establish how the anomalous states can be mapped onto the normal states. Topological insulators are bulk electronic insulators with symmetry-protected gapless modes on their surfaces1,2,3,4,5. Breaking time-reversal symmetry in these systems via ferromagnetism induces a gapped state characterized by a zero magnetic field quantized Hall response—the quantum anomalous Hall (QAH) state6,7,8. A key question that has remained experimentally unexplored is the relationship of this new type of quantum Hall (QH) state with the previously known orbitally driven QH states. Here, we show experimentally that a ferromagnetic topological insulator exhibiting the QAH state is well described by the global phase diagram of the QH effect. By mapping the conductivity tensor in the vicinity of the QAH phase, we find evidence for quantum criticality and delocalization behaviour9,10 that can quantitatively be described by the renormalization group properties of the QH ground state11,12. This result demonstrates that this QAH state can be understood within the context of the law of corresponding states that governs the QH state13,14.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/01556c34f3a2567c77d84fb33382fdd4f47c5bfe

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

In Materials Chemistry

Citations in the corpus

Interface-Induced Phenomena in Magnetism (2016, unknown): “Further, when the chemical potential of a ferromagnetic topological insulator thin film is tuned within the magnetic gap via electrical gating, helical 2D Dirac fermions transition to 1D chiral edge states of a quantum anomalous Hall insulator [Yu et al., 2010a; Chang et al., 2013a; Checkelsky et al”
Gapless Surface Dirac Cone in Antiferromagnetic Topological Insulator MnBi2Te4 (2019, background): “the QAH effect and the axion state have been discovered in TIs and magnetic topological heterostructures where ferromagnetically ordered moments are induced by chemical doping [8–12], an intrinsic, stoichiometric magnetic topological insulator (MTI) is highly desired in both cases, as the emerging t”
Colloquium : Quantum anomalous Hall effect (2022, background): “…of a QAH effect in MBEfabricated Cr-doped TI thin films was relatively quickly reproduced by many research groups (Bestwick et al., 2015; Checkelsky et al., 2014; Kandala et al., 2015; Kawamura et al., 2017; Kou et al., 2014; Lachman et al., 2015; Liu et al., 2016b), using film…”
Dirac Surface States in Intrinsic Magnetic Topological Insulators EuSn2As2 and MnBi2nTe3n+1 (2019, background): “The introduction of magnetism into the Z2 TIs can produce more exotic topological quantum phenomena, such as the quantum anomalous Hall effect [8-14], axion insulator states [15-21] and chiral Majorana fermions [22].”
High-temperature quantum anomalous Hall regime in a MnBi2Te4/Bi2Te3 superlattice (2020, background): “The ambipolar behavior centered near zero voltage is direct evidence for type conversion [33, 34], while the minimum in Rxx points to the presence of chiral edge channels on the gapped surfaces [2, 3] coexisting with 2DEG longitudinal conductance channels.”