Physical review. B, Condensed matter
Static and dynamic critical behavior of extended-defectN-component systems in cubic anisotropic crystals
Yoshitake Yamazaki, Arno Holz, Moyuru Ochiai, Yoshiichi Fukuda
Abstract
We study the static and dynamic critical behavior of N-component spin systems in crystals with cubic anisotropy in the presence of extended defects, namely ${\ensuremath{\epsilon}}_{d}$-dimensionally connected defects distributed randomly in d-${\ensuremath{\epsilon}}_{d}$ dimensions. These defects make the systems coordinate anisotropic. As a result of the presence of the cubic anisotropy and the coordinate anisotropy, various new types of critical behavior appear, e.g., an ${\ensuremath{\epsilon}}^{1/2}$ (\ensuremath{\epsilon}\ensuremath{\equiv}4-d) expansion for extended-defect XY systems, spiral trajectories, and oscillatory critical behavior for extended-defect systems, first-order phase transitions for extended-defect N-component systems with 2\ensuremath{\le}N<4 near the stability boundary of the free energy, and so on. The first two types of behavior will be investigated in detail.