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arXiv · 1009.5719

Entropy driven formation of a half-quantum vortex lattice

Suk Bum Chung·Steven A. Kivelson
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Abstract

Half-quantum vortices (HQVs) can exist in a superconductor or superfluid with an exact or approximate U(1) \times U(1) symmetry, for instance in spinor condensates, 3He-A, Sr2RuO4, 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.

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Suk Bum Chung, Steven A. Kivelson. 2011-01-14. Entropy driven formation of a half-quantum vortex lattice. https://doi.org/10.1103/physrevb.82.214512

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