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arXiv · 2401.08744

Gapless Fermionic Systems as Phase-space Topological Insulators: Non-perturbative Results from Anomalies

Taylor L. Hughes·Yuxuan Wang
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Abstract

We present a theory unifying the topological responses and anomalies of various gapless fermion systems exhibiting Fermi surfaces, including those with Berry phases, and nodal structures, which applies beyond non-interacting limit. As our key finding, we obtain a general approach to directly relate gapless fermions and topological insulators in phase space, including first- and higher-order insulators. Using this relation we show that the low-energy properties and response theories for gapless fermionic systems can be directly obtained without resorting to microscopic details. Our results provide a unified framework for describing such systems using well-developed theories from the study of topological phases of matter.

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Taylor L. Hughes, Yuxuan Wang. 2024-01-16. Gapless Fermionic Systems as Phase-space Topological Insulators: Non-perturbative Results from Anomalies. https://doi.org/10.1103/physrevb.110.l121119

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