\n\nThe concept of entanglement spectrum, which was previously associated with gapped topological phases, is extended to the gapless Weyl semimetal phase. By dimensional reduction, we numerically investigate entanglement spectra of Weyl semimetal phases in two three-dimensional (3D) lattice models consisting of coupled layers of 2D quantum anomalous Hall insulators. It is found that for the gapless phase, there still exists a correspondence between the entanglement surface state and the physical surface state; and the “trace index”, defined as the discontinuity in the trace of the single-particle entanglement spectrum, remains equivalent to the Chern number of the 2D insulator layers.\n\n\nThe concept of entanglement spectrum, which was previously associated with gapped topological phases, is extended to the gapless Weyl semimetal phase. By dimensional reduction, we numerically investigate entanglement spectra of Weyl semimetal phases in two three-dimensional (3D) lattice models consisting of coupled layers of 2D quantum anomalous Hall insulators. It is found that for the gapless phase, there still exists a correspondence between the entanglement surface state and the physical surface state; and the “trace index”, defined as the discontinuity in the trace of the single-particle entanglement spectrum, remains equivalent to the Chern number of the 2D insulator layers.\n

Europhysics Letters (EPL)Aug 1, 20145 citations

Entanglement Chern number for three-dimensional topological insulators: Characterization by Weyl points of entanglement Hamiltonians

Hiromu Araki, Takahiro Fukui, Yasuhiro Hatsugai

We propose characterization of the three-dimensional topological insulator by using the Chern number for the entanglement Hamiltonian (entanglement Chern number). Here we take the extensive spin partition of the system, that pulls out the quantum entanglement between up spin and down spin of the many-body ground state. In three dimensions, the topological insulator phase is described by the section entanglement Chern number, which is the entanglement Chern number for a periodic plane in the Brillouin zone. The section entanglement Chern number serves as an interpolation of the ${\mathbb{Z}}_{2}$ invariants defined on time-reversal invariant planes. We find that the change of the section entanglement Chern number protects the Weyl point of the entanglement Hamiltonian, and the parity of the number of Weyl points distinguishes the strong topological insulator phase from the weak topological insulator phase.We propose characterization of the three-dimensional topological insulator by using the Chern number for the entanglement Hamiltonian (entanglement Chern number). Here we take the extensive spin partition of the system, that pulls out the quantum entanglement between up spin and down spin of the many-body ground state. In three dimensions, the topological insulator phase is described by the section entanglement Chern number, which is the entanglement Chern number for a periodic plane in the Brillouin zone. The section entanglement Chern number serves as an interpolation of the ${\mathbb{Z}}_{2}$ invariants defined on time-reversal invariant planes. We find that the change of the section entanglement Chern number protects the Weyl point of the entanglement Hamiltonian, and the parity of the number of Weyl points distinguishes the strong topological insulator phase from the weak topological insulator phase.

arXiv:1708.03722Physical review. B./Physical review. BOct 23, 20176 citations

Entanglement Spectrum In Topological Phasess

Bogdan Andrei Bernevig

Bulletin of the American Physical SocietyMar 1, 20120 citations

{\mathbb{Z}}_{2}

invariants defined on time-reversal invariant planes. We find that the change of the section entanglement Chern number protects the Weyl point of the entanglement Hamiltonian, and the parity of the number of Weyl points distinguishes the strong topological insulator phase from the weak topological insulator phase.