Supersolid phase of three-dimensional spin and lattice-boson models

8 April 2010 (Thu), 15:00 pm -

8F seminar room, Central Bldg., Sengen site

Dr. Hiroaki Ueda (植田浩明博士)

Yukawa Institute for Theoretical Physics, Kyoto University (京都大学基礎物理学研究所)

Supersolid phase of three-dimensional spin and lattice-boson models / 3次元磁性体および格子上のボソンモデルの超固体状態

We investigate the stability of solid and supersolid (SS) phases of three-dimensional spin and hardcore-boson models on a body-centered cubic lattice. This lattice boson model was applied to a study of the low-temperature physics in 4He, and Liu and Fisher concluded the SS phase for 4He within the mean-field approximation. To see quantum effects on the stability of the SS phase, we reconsider this model from the viewpoint of Bose-Einstein condensation of vacancies (interstitials) in the solid. We find that quantum fluctuations can be strong enough to destabilize not only the solid phase but also the SS phase for a parameter set believed to be appropriate to 4He.

Dr. Hiroyuki Yamase(山瀬博之)