Nonreciprocal Disorder Prevents Zero-Temperature Freezing in a Ferromagnet

Noah Grodzinski; Robert L. Jack; Sarah A. M. Loos

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arXiv · 2606.21582

Nonreciprocal Disorder Prevents Zero-Temperature Freezing in a Ferromagnet

Noah Grodzinski·Robert L. Jack·Sarah A. M. Loos

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Abstract

Nonreciprocal interactions underpin diverse nonequilibrium phenomena, yet the effects of quenched nonreciprocity in extended systems remain largely unexplored. We study a $2d$ Ising model with randomly distributed nonreciprocal bonds at density $p$, finding a continuous nonequilibrium transition down to $T=0$ with finite $p_c$. A gauge-invariance argument yields $p_c(T)\leq1/2$, and mean-field theory predicts a qualitatively correct phase diagram. Unlike equilibrium disordered models, the zero-temperature dynamics remains active, with athermal rare-region reversals and logarithmic "activated" coarsening.

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Noah Grodzinski, Robert L. Jack, Sarah A. M. Loos. 2026-06-19. Nonreciprocal Disorder Prevents Zero-Temperature Freezing in a Ferromagnet. https://arxiv.org/abs/2606.21582

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