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arXiv · 2312.12546

Conformal field theories in a magnetic field

Rufus Boyack·Luca V. Delacrétaz·Éric Dupuis·William Witczak-Krempa
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Abstract

We study the properties of 2+1d conformal field theories (CFTs) in a background magnetic field. Using generalized particle-vortex duality, we argue that in many cases of interest the theory becomes gapped, which allows us to make a number of predictions for the magnetic response, background monopole operators, and more. Explicit calculations at large N for Wilson-Fisher and Gross-Neveu CFTs support our claim, and yield the spectrum of background (defect) monopole operators. Finally, we point out that other possibilities exist: certain CFTs can become metallic in a magnetic field. Such a scenario occurs for a Dirac fermion coupled to a Chern-Simons gauge field, where a non-Fermi liquid is argued to emerge.

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Rufus Boyack, Luca V. Delacrétaz, Éric Dupuis, William Witczak-Krempa. 2023-12-19. Conformal field theories in a magnetic field. https://arxiv.org/abs/2312.12546

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