Spin-Peierls instability of deconfined quantum critical points

Fuente: arXiv
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Main Authors: Hofmeier, David, Willsher, Josef, Seifert, Urban F. P., Knolle, Johannes
Format: Preprint
Published: 2024
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_version_ 1866909315905880064
author Hofmeier, David
Willsher, Josef
Seifert, Urban F. P.
Knolle, Johannes
author_facet Hofmeier, David
Willsher, Josef
Seifert, Urban F. P.
Knolle, Johannes
contents Deconfined quantum critical points (DQCPs) are putative phase transitions beyond the Landau paradigm with emergent fractionalized degrees of freedom. The original example of a DQCP is the spin-1/2 quantum antiferromagnet on the square lattice which features a second order transition between valence bond solid (VBS) and Néel order. The VBS order breaks a lattice symmetry, and the corresponding VBS order parameter may couple to lattice distortion modes (phonons) at appropriate momenta. We investigate a field-theoretic description of the DQCP in the presence of such a spin-lattice coupling. We show that treating phonons as classical lattice distortions leads to a relevant monopole-phonon interaction inducing an instability towards a distorted lattice by an analogous mechanism to the spin-Peierls instability in one dimension. Consequently, there is a breakdown of the DQCP which generally becomes a strong first-order transition. Taking into account the full quantum nature of the phonons, we argue that the continuous DQCP persists above a critical phonon frequency. Lastly, we comment on the connection to general gapless, deconfined gauge theories.
format Preprint
id arxiv_https___arxiv_org_abs_2406_12729
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Spin-Peierls instability of deconfined quantum critical points
Hofmeier, David
Willsher, Josef
Seifert, Urban F. P.
Knolle, Johannes
Strongly Correlated Electrons
High Energy Physics - Theory
Deconfined quantum critical points (DQCPs) are putative phase transitions beyond the Landau paradigm with emergent fractionalized degrees of freedom. The original example of a DQCP is the spin-1/2 quantum antiferromagnet on the square lattice which features a second order transition between valence bond solid (VBS) and Néel order. The VBS order breaks a lattice symmetry, and the corresponding VBS order parameter may couple to lattice distortion modes (phonons) at appropriate momenta. We investigate a field-theoretic description of the DQCP in the presence of such a spin-lattice coupling. We show that treating phonons as classical lattice distortions leads to a relevant monopole-phonon interaction inducing an instability towards a distorted lattice by an analogous mechanism to the spin-Peierls instability in one dimension. Consequently, there is a breakdown of the DQCP which generally becomes a strong first-order transition. Taking into account the full quantum nature of the phonons, we argue that the continuous DQCP persists above a critical phonon frequency. Lastly, we comment on the connection to general gapless, deconfined gauge theories.
title Spin-Peierls instability of deconfined quantum critical points
topic Strongly Correlated Electrons
High Energy Physics - Theory
url https://arxiv.org/abs/2406.12729