We develop a multiorder parameter mean-field formalism for systems of coupled quantum rotors. The scheme is developed to account for systems where ortho-para distinction is valid. We apply our formalism to solid H-2 and D-2. We find an anomalous reentrant orientational phase transition for both systems at thermal equilibrium. The correlation functions of the order parameter indicate short-range order at low temperatures. As the temperature is increased the correlation increases along the phase boundary. We also find that even extremely small odd-J concentrations (1%) can trigger short-range orientational ordering.
Theoretical evidence for a reentrant phase diagram in ortho-para mixtures of solid H-2 at high pressure / B., Hetenyi; S., Scandolo; Tosatti, Erio. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 94:12(2005), pp. 1-4. [10.1103/PhysRevLett.94.125503]
Theoretical evidence for a reentrant phase diagram in ortho-para mixtures of solid H-2 at high pressure
Tosatti, Erio
2005-01-01
Abstract
We develop a multiorder parameter mean-field formalism for systems of coupled quantum rotors. The scheme is developed to account for systems where ortho-para distinction is valid. We apply our formalism to solid H-2 and D-2. We find an anomalous reentrant orientational phase transition for both systems at thermal equilibrium. The correlation functions of the order parameter indicate short-range order at low temperatures. As the temperature is increased the correlation increases along the phase boundary. We also find that even extremely small odd-J concentrations (1%) can trigger short-range orientational ordering.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.