Quantum Monte Carlo study of the formation of molecular polarizations and the antiferroelectric ordering in squaric acid crystals

Abstract

Effects of geometrical frustration and quantum fluctuation are theoretically investigated for the proton ordering in a quasi-two-dimensional hydrogen-bonded system, squaric acid crystal. We elucidate the phase diagram for an effective model, the transverse-field Ising model on a frustrated checkerboard lattice, by using quantum Monte Carlo simulation. A crossover to liquidlike paraelectric state with well-developed molecular polarizations is identified, distinguishably from long-range ordering. Emergence of long-range order from the liquidlike state exhibits peculiar aspects originating from the lifting of quasi-macroscopic degeneracy, such as colossal enhancement of the transition temperature and a vanishingly small anomaly in the specific heat.

6 pages, 4 figures, accepted for publication in Physical Review B

References in corpus (2)

• Ising models of quantum frustration
• Efficient Monte Carlo algorithm in quasi-one-dimensional Ising spin systems

Cited by in corpus (8)

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• Ab initio simulations of hydrogen-bonded ferroelectrics: collective tunneling and the origin of geometrical isotope effects
• Effects of diagonal strains and H-bond geometry in antiferroelectric squaric acid crystals
• Quantum valence bond ice theory for proton-driven quantum spin-dipole liquids
• Flux roughening in spin ice with mixed $\pm J$ interactions
• Dipole-dipole interaction induced phases in Hydrogen-bonded squaric acid crystal
• Deconfinement of electric charges in hydrogen-bonded ferroelectrics
• Ground state many-body quantum entanglement of frustrated transverse field models on square lattice