A Quantum d-Dimensional Random-Field XY Ferromagnet |
| |
| Authors: | MA YuQiang |
| |
| Affiliation: | Department of Physics, Nanjing University, Nanjing 210093, China |
| |
| Abstract: | We propose a soluble quantum spherical XY ferromagnet with a random field in the boson space. We obtain a general expression of the critical temperat ure Tc below which the ordered ferromagnet phase appears. The Imry-Ma result concerning the lower critical dimension dc = 4 is recovered, and the critical exponents near the critical temperature Tc are calculated. We show that the random-field fluctuations rather than the quantum fluctuations dominate the phase transition and critical behavior of the system. The entropy vanishes as Td/2 at low temperatures, contrary to the classical spherical model. |
| |
| Keywords: | phase transition XY model |
|
| 点击此处可从《理论物理通讯》浏览原始摘要信息 |
|
点击此处可从《理论物理通讯》下载全文 |
|
