Generic reduction theory for Fermi sea topology in metallic systems

Fuente: arXiv
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Main Author: Jia, Wei
Format: Preprint
Published: 2024
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author Jia, Wei
author_facet Jia, Wei
contents The Fermi sea of a metal can host exotic quantum topology, which governs its conductance quantization and is characterized by the Euler characteristic ($χ_F$). In contrast to the well-known band topology, which is determined by the global features of wave functions, the topology of such metallic systems is intrinsically linked to the geometry of the Fermi sea. As a result, probing and identifying $χ_F$ in high-dimensional systems presents a challenge. Here, we propose a generic dimensional reduction theory for the Fermi sea topology in $d$-dimensional metallic systems, showing that $χ_F$ can be determined by the features of so-called reduced critical points on Fermi surfaces. Moreover, we reveal that $χ_F$ can be interpreted as a topological invariant of band topology by mapping a metallic system to a gapped system. Building on this nontrivial result, we identify a broad class of topological superconductors (SCs) whose topological numbers are precisely determined by the $χ_F$ of their normally filled bands. This provides an indirect method to capture $χ_F$ by measuring the (pseudo)spin polarizations of these topological SCs. Our findings are expected to significantly advance research into Fermi sea topology.
format Preprint
id arxiv_https___arxiv_org_abs_2403_19125
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Generic reduction theory for Fermi sea topology in metallic systems
Jia, Wei
Mesoscale and Nanoscale Physics
Quantum Gases
Superconductivity
The Fermi sea of a metal can host exotic quantum topology, which governs its conductance quantization and is characterized by the Euler characteristic ($χ_F$). In contrast to the well-known band topology, which is determined by the global features of wave functions, the topology of such metallic systems is intrinsically linked to the geometry of the Fermi sea. As a result, probing and identifying $χ_F$ in high-dimensional systems presents a challenge. Here, we propose a generic dimensional reduction theory for the Fermi sea topology in $d$-dimensional metallic systems, showing that $χ_F$ can be determined by the features of so-called reduced critical points on Fermi surfaces. Moreover, we reveal that $χ_F$ can be interpreted as a topological invariant of band topology by mapping a metallic system to a gapped system. Building on this nontrivial result, we identify a broad class of topological superconductors (SCs) whose topological numbers are precisely determined by the $χ_F$ of their normally filled bands. This provides an indirect method to capture $χ_F$ by measuring the (pseudo)spin polarizations of these topological SCs. Our findings are expected to significantly advance research into Fermi sea topology.
title Generic reduction theory for Fermi sea topology in metallic systems
topic Mesoscale and Nanoscale Physics
Quantum Gases
Superconductivity
url https://arxiv.org/abs/2403.19125