Generating and detecting topological phases with higher Chern number
| Autor: | David L. Feder, Abhijeet Alase |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Condensed Matter::Quantum Gases
Physics Chern class Lattice (group) FOS: Physical sciences Fermion Coupling (probability) Topology 01 natural sciences 010305 fluids & plasmas Brillouin zone Quantum Gases (cond-mat.quant-gas) 0103 physical sciences Hexagonal lattice Condensed Matter - Quantum Gases 010306 general physics Spin (physics) Realization (systems) |
| Zdroj: | Physical Review A. 103 |
| ISSN: | 2469-9934 2469-9926 |
| DOI: | 10.1103/physreva.103.053305 |
| Popis: | Topological phases with broken time-reversal symmetry and Chern number |C|>=2 are of fundamental interest, but it remains unclear how to engineer the desired topological Hamiltonian within the paradigm of spin-orbit-coupled particles hopping only between nearest neighbours of a static lattice. We show that phases with higher Chern number arise when the spin-orbit coupling satisfies a combination of spin and spatial rotation symmetries. We leverage this result both to construct minimal two-band tight binding Hamiltonians that exhibit |C|=2,3 phases, and to show that the Chern number of one of the energy bands can be inferred from the particle spin polarization at the high-symmetry crystal momenta in the Brillouin zone. Using these insights, we provide a detailed experimental scheme for the specific realization of a time-reversal-breaking topological phase with |C|=2 for ultracold atomic gases on a triangular lattice subject to spin-orbit coupling. The Chern number can be directly measured using Zeeman spectroscopy; for fermions the spin amplitudes can be measured directly via time of flight, while for bosons this is preceded by a short Bloch oscillation. Our results provide a pathway to the realization and detection of novel topological phases with higher Chern number in ultracold atomic gases. 12 pages, 4 figures |
| Databáze: | OpenAIRE |
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