Strings, commensurate and incommensurate vortices in XY models (invited) (abstract)
ISSN: |
1089-7550
|
---|---|
Source: |
AIP Digital Archive
|
Topics: |
Physics
|
Notes: |
A class of simple, translationally invariant, nearest-neighbor, isotropic XY models that possess novel topological defects will be presented.1,2 As the first example, I shall present a model that exhibits, in addition to integer vortices, half-integer-vortex, and "string'' excitations. The interaction between the half-integer vortices is a superposition of the usual logarithmic Coulomb potential and a linear potential mediated by the strings. Due to these new excitations the system possesses a rich phase diagram. As the second example, I shall present a model that supports commensurate and incommensurate vortices. Due to a novel ground-state degeneracy, the "charges'' of the incommensurate vortices are fixed by their cost in zero-point entropy and are independent of the parameters in the Hamiltonian. Again, as a result of these new defects the model exhibits a very rich phase diagram.
|
Type of Medium: |
Electronic Resource
|
URL: |