ISSN:
1572-9613
Keywords:
Two-dimensional systems
;
phase transitions
;
frustratedXY models
;
topological excitations
;
fractional vortices
;
Josephson junctions
;
superfluid3He-A thin films
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract For two-dimensional uniformly frustratedXY models the group of symmetry spontaneously broken in the ground state is a cross product of the group of two-dimensional rotations by some discrete group of finite order. Different possibilities of phase transitions in such systems are investigated. The transition to the Coulomb gas with noninteger charges is widely used when analyzing the properties of relevant topological excitations. The number of these excitations includes not only domain walls and traditional (integer) vortices, but also vortices with a fractional number of circulation quanta which are to be localized at bends and intersections of domain walls. The types of possible phase transitions prove to be dependent on their relative sequence: in the case the vanishing of domain wall free energy occurs earlier (at increasing temperature) than the dissociation of pairs of ordinary vortices, the second phase transition is to be associated with dissociation of pairs of fractional vortices. The general statements are illustrated with a number of examples.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01010570
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