TY - JOUR
T1 - Entropy-driven formation of a half-quantum vortex lattice
AU - Chung, Suk Bum
AU - Kivelson, Steven A.
PY - 2010/12/14
Y1 - 2010/12/14
N2 - Half-quantum vortices (HQVs) can exist in a superconductor or superfluid with an exact or approximate U (1) ×U (1) symmetry, for instance, in spinor condensates, H3 e-A, Sr2 RuO4, and possibly cuprate superconductors with stripe order. In this paper, we show that a lattice of HQVs can be stabilized at finite temperature even when it does not have lower energy than the lattice of full vortices at T=0 since there is a gain in configurational entropy when a full vortex fractionalizes into a pair of HQVs. Specifically, the lattice of HQVs has an optical branch of phonon modes absent in the lattice of full vortices. Moreover, the HQV lattice at T>0 can have a different structure than the HQV lattice at T=0.
AB - Half-quantum vortices (HQVs) can exist in a superconductor or superfluid with an exact or approximate U (1) ×U (1) symmetry, for instance, in spinor condensates, H3 e-A, Sr2 RuO4, and possibly cuprate superconductors with stripe order. In this paper, we show that a lattice of HQVs can be stabilized at finite temperature even when it does not have lower energy than the lattice of full vortices at T=0 since there is a gain in configurational entropy when a full vortex fractionalizes into a pair of HQVs. Specifically, the lattice of HQVs has an optical branch of phonon modes absent in the lattice of full vortices. Moreover, the HQV lattice at T>0 can have a different structure than the HQV lattice at T=0.
UR - http://www.scopus.com/inward/record.url?scp=78650824028&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.82.214512
DO - 10.1103/PhysRevB.82.214512
M3 - Article
AN - SCOPUS:78650824028
SN - 1098-0121
VL - 82
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 21
M1 - 214512
ER -