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This study provides numerical validation for Nahum's field theory predictions regarding spontaneous U(1) symmetry breaking in one-dimensional spin chains with biquadratic interactions. The findings confirm critical exponents consistent with epsilon-expansion results, offering deeper insight into the phase transitions of strongly correlated quantum systems. Such theoretical advances are fundamental to understanding the limits of quantum coherence and order in low-dimensional materials.
Criticality enabled long-range order in a U(1)-symmetric spin-1 Heisenberg chain with biquadratic interactions
arXiv:2609.31319v1 Announce Type: cross Abstract: In a recent paper Nahum argued on the basis of a renormalization-group analysis that, contrary to standard lore, ground states of 1D spin chains with short-range interactions can spontaneously break U(1) ``easy-plane'' spin rotation symmetry. True long-range order of $(S^x,S^y)$ arises at the phase transition between two quasi-long-range-ordered phases. Here we present detailed numerical results for an anisotropic spin-1 chain model. We find a magnetization exponent $\beta\approx0.29$, consistent with the $\epsilon$-expansion prediction $\beta\approx0.28$, a divergence of the Luttinger parameter on approaching the transition from both sides with an exponent that we relate to Nahum's transition, and finite-size spectra consistent with a dynamical critical exponent $z\approx2$. Our results support the critical behavior predicted by Nahum's field theory.
Abstract:In a recent paper Nahum argued on the basis of a renormalization-group analysis that, contrary to standard lore, ground states of 1D spin chains with short-range interactions can spontaneously break U(1) ``easy-plane'' spin rotation symmetry. True long-range order of $(S^x,S^y)$ arises at the phase transition between two quasi-long-range-ordered phases. Here we present detailed numerical results for an anisotropic spin-1 chain model. We find a magnetization exponent $\beta\approx0.29$, consistent with the $\epsilon$-expansion prediction $\beta\approx0.28$, a divergence of the Luttinger parameter on approaching the transition from both sides with an exponent that we relate to Nahum's transition, and finite-size spectra consistent with a dynamical critical exponent $z\approx2$. Our results support the critical behavior predicted by Nahum's field theory.
Strongly Correlated Electrons (cond-mat.str-el); Quantum Physics (quant-ph)
arXiv:2609.31319 [cond-mat.str-el]
(or arXiv:2609.31319v1 [cond-mat.str-el] for this version)
https://doi.org/10.48550/arXiv.2609.31319 Focus to learn more arXiv-issued DOI via DataCite (pending registration)
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