Weyl semimetal with broken time reversal and inversion symmetries
By A. Zyuzin, Si Wu, A. Burkov. 2012
280 citations recorded by the source corpus.
Weyl semimetal is a new topological state of matter, characterized by the presence of nondegenerate band-touching nodes, separated in momentum space, in its bandstructure. Here we discuss a particular realization of a Weyl semimetal: a superlattice heterostructure, made of alternating layers of topological insulator (TI) and normal insulator (NI) material, introduced by one of us before. The Weyl node splitting is achieved most easily in this system by breaking time-reversal (TR) symmetry, for example by magnetic doping. If, however, spatial inversion (I) symmetry remains, the Weyl nodes will occur at the same energy, making it possible to align the Fermi energy simultaneously with both nodes. The goal of this work is to explore the consequences of breaking the I symmetry in this system. We demonstrate that, while this generally moves the Weyl nodes to different energies, thus eliminating nodal semimetal and producing a state with electron and hole Fermi surfaces, the topological properties of the Weyl semimetal state, i.e. the chiral edge states and the corresponding Hall conductivity, survive for moderate I symmetry breaking. Moreover, we demonstrate that a new topological phenomenon arises in this case, if an external magnetic field along the growth direction of the heterostructure is applied. Namely, this leads to an equilibrium dissipationless current, flowing along the direction of the field, whose magnitude is proportional to the energy difference between the Weyl nodes and to the magnetic field, with a universal coefficient, given by a combination of fundamental constants.
Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry
View Paper: https://www.semanticscholar.org/paper/11c54fad5e3782430e27ba1197715b83ae542043
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In Atomic and Molecular Physics, and Optics
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Citations in the corpus
- Topological Semimetals from First Principles (2018, background): “Another route, which is not unrelated to the former, has led to proposals based on the heterostructure principle, where layers of topological insulator and normal insulator are stacked to form a superlattice (10, 92, 93).”
- Inhomogeneous Weyl and Dirac Semimetals: Transport in Axial Magnetic Fields and Fermi Arc Surface States from Pseudo-Landau Levels (2016, background): “[31] A A Zyuzin, Si Wu, and A A Burkov, “Weyl semimetal with broken time reversal and inversion symmetries,” Phys.”
- Weyl Semimetal Phase in Noncentrosymmetric Transition-Metal Monophosphides (2014, background): “The first one is a superlattice system formed by alternatively stacking normal and topological insulators [19,20].”
- Observation of Weyl nodes in TaAs (2015, background): “ transition-metal monophosphide TaAs has been predicted to be a Weyl semimetal (WSM), and twelve pairs of Weyl nodes are expected in its 3D Brillouin zone (BZ) [10, 11]. Compared with other proposals [7, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22] in realizing a Weyl state, the TaAs family is featur”
- Experimental discovery of Weyl semimetal TaAs (2015, unknown): “Unlike the previously proposed WSMs which are usually complex materials tailored by fine-tuning methods [29–34], TaAs is predicted to be a WSM in its natural state [35,36].”
- Weyl and Dirac semimetals in three-dimensional solids (2017, background): “Both CME and the anomalous Hall effect in WSMs can be represented compactly by the addition of the so-called axion term to the electromagnetic Lagrangian (Goswami and Tewari, 2013; Grushin, 2012; Son and Yamamoto, 2012; Vazifeh and Franz, 2013a; Zyuzin and Burkov, 2012; Zyuzin et al., 2012).”