collaborators

5 papers

cond-mat.str-el2026

Topological Phase Transitions and Their Thermodynamic Fate in Arbitrary- Pyrochlore Spin Ice

Sena Watanabe, Yukitoshi Motome, Haruki Watanabe

We develop a self-contained theoretical framework that classifies the topological phases and critical phenomena of classical pyrochlore magnets with arbitrary spin , subject to…

cond-mat.str-el2026

Continuous crossover between high-pressure ice phases VII and X driven by monopole screening: a model study

Sena Watanabe, Yukitoshi Motome, Haruki Watanabe

The proton-disordered molecular phase of water ice (ice-VII) and its ultrahigh-pressure non-molecular phase (ice-X) share identical macroscopic crystal symmetry (space group $Pn\ba…

cond-mat.str-el2026

Dualities and Topological Classification of the Pyrochlore Spin Ice

Sena Watanabe, Yukitoshi Motome, Haruki Watanabe

We resolve the phase diagram of the pyrochlore spin ice, which exhibits trivial paramagnetic, U(1) Coulomb, and spin nematic phases. In the monopole-free limit, the system ca…

cond-mat.str-el2025

Quasi-local Frustration-Free Free Fermions

Shunsuke Sengoku, Hoi Chun Po, Haruki Watanabe

Recent studies have revealed that frustration-free models, expressed as sums of finite-range interactions or hoppings, exhibit several properties markedly different from those of f…

cond-mat.stat-mech2025

Rigorous lower bound of the dynamical critical exponent of the Ising model

Rintaro Masaoka, Tomohiro Soejima, Haruki Watanabe

We study the kinetic Ising model under Glauber dynamics and establish an upper bound on the spectral gap for finite systems. This bound implies the critical exponent inequality $z…