Tuesday, October 9, 2012

1210.2383 (Sergei Khlebnikov)

Winding branes and persistent currents    [PDF]

Sergei Khlebnikov
A D5 brane winding around a stack of D3 branes can be used as a model of persistent current in a thin superconducting ring, with the number N of D3s corresponding to the number of transverse channels in the ring. We consider, in the large N limit, classical and quantum stability of a superconducting state with a uniform winding number density q. We find that there is a classical superconducting solution with any q, no matter how large, but for q larger than a certain q_m it is only metastable and can decay into a state with a smaller q by quantum phase slips. We argue that the decay produces strings via a version of the Hanany-Witten effect (in a non-transverse, non-supersymmetric arrangement of branes). This parallels the requirement of quasiparticle production in a clean (disorder-free) wire in field theory of superconductivity.
View original: http://arxiv.org/abs/1210.2383

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