Measuring quantized circular dichroism in ultracold topological matter
By L. Asteria, Duc-Thanh Tran, T. Ozawa, M. Tarnowski, B. Rem, N. Fläschner, Klaus Sengstock, Nathan Goldman, C. Weitenberg. Nature Physics, 2018
179 citations recorded by the source corpus.
The topology of two-dimensional materials traditionally manifests itself through the quantization of the Hall conductance, which is revealed in transport measurements1–3. Recently, it was predicted that topology can also give rise to a characteristic spectroscopic response on subjecting a Chern insulator to a circular drive: comparing the frequency-integrated depletion rates associated with drives of opposite orientation leads to a quantized response dictated by the topological Chern number of the populated Bloch band4,5. Here we experimentally demonstrate this intriguing topological effect using ultracold fermionic atoms in topological Floquet bands. In addition, our depletion-rate measurements also provide an experimental estimation of the Wannier-spread functional, a fundamental geometric property of Bloch bands related to the quantum metric6,7. Our results establish topological spectroscopic responses as a versatile probe, which could be applied to access the geometry and topology of many-body quantum systems, such as fractional Chern insulators8.By subjecting a Chern insulator to a circular drive, its geometrical and topological properties would be accessible from the spectroscopic response. This prediction is now confirmed in a Floquet topological system realized by ultracold fermionic atoms.
Subfields: Atomic and Molecular Physics, and Optics
View Paper: https://www.semanticscholar.org/paper/ea8bbbdbc4b19436188f4ca51fc30be17240fc10
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In Atomic and Molecular Physics, and Optics
Citations in the corpus
- Realization of an anomalous Floquet topological system with ultracold atoms (2020, background): “In cold-atom systems a number of experimental techniques has been developed to determine the geometric properties of Floquet quasienergy bands in analogy to their static counterparts [14, 18–22].”