Quantum scaling of the spin lattice relaxation rate in the checkerboard $J$-$Q$ model

Fuente: arXiv
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Autori principali: Li, Chengchen, Lin, Huihang, Yu, Rong
Natura: Preprint
Pubblicazione: 2024
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author Li, Chengchen
Lin, Huihang
Yu, Rong
author_facet Li, Chengchen
Lin, Huihang
Yu, Rong
contents Motivated by recent progress on the experimental realization of proximate deconfined quantum critical point in a frustrated quantum magnet, we study the low-energy spin dynamics of a related checkerboard $J$-$Q$ model by using quantum Monte Carlo simulations. The ground state of this model undergoes a weakly first-order quantum phase transition with an emergent $O(4)$ symmetry between an antiferromagnetic state and a plaquette valence bond solid. The calculated spin lattice relaxation rate of nuclear magnetic resonance, $1/T_1$, exhibits distinct low-temperature behaviors depending on the ground states. With decreasing the temperature, $1/T_1$ rises up on the antiferromagnetic side, characterizing a crossover to the renormalized classical regime, whereas $1/T_1$ drops exponentially on the side of valence bond solid, reflecting the gap opening in the plaquette ordered phase. The extracted spin gap scales with the distance to the transition point as a power-law with an exponent $ϕ\approx0.3$, consistent with the scaling ansatz $ϕ=νz$ with $ν\approx0.3$ and $z=1$. Near the quantum phase transition, the temperature dependent $1/T_1$ shows a broad crossover regime where a universal scaling $1/T_1\sim T^η$ with $η\approx0.6$ is found. Our results suggest a quantum scaling regime associated with the emergent enhanced symmetry near this first-order quantum phase transition.
format Preprint
id arxiv_https___arxiv_org_abs_2402_17418
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Quantum scaling of the spin lattice relaxation rate in the checkerboard $J$-$Q$ model
Li, Chengchen
Lin, Huihang
Yu, Rong
Strongly Correlated Electrons
Motivated by recent progress on the experimental realization of proximate deconfined quantum critical point in a frustrated quantum magnet, we study the low-energy spin dynamics of a related checkerboard $J$-$Q$ model by using quantum Monte Carlo simulations. The ground state of this model undergoes a weakly first-order quantum phase transition with an emergent $O(4)$ symmetry between an antiferromagnetic state and a plaquette valence bond solid. The calculated spin lattice relaxation rate of nuclear magnetic resonance, $1/T_1$, exhibits distinct low-temperature behaviors depending on the ground states. With decreasing the temperature, $1/T_1$ rises up on the antiferromagnetic side, characterizing a crossover to the renormalized classical regime, whereas $1/T_1$ drops exponentially on the side of valence bond solid, reflecting the gap opening in the plaquette ordered phase. The extracted spin gap scales with the distance to the transition point as a power-law with an exponent $ϕ\approx0.3$, consistent with the scaling ansatz $ϕ=νz$ with $ν\approx0.3$ and $z=1$. Near the quantum phase transition, the temperature dependent $1/T_1$ shows a broad crossover regime where a universal scaling $1/T_1\sim T^η$ with $η\approx0.6$ is found. Our results suggest a quantum scaling regime associated with the emergent enhanced symmetry near this first-order quantum phase transition.
title Quantum scaling of the spin lattice relaxation rate in the checkerboard $J$-$Q$ model
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2402.17418