Sine-Gordon description of Beresinskii-Kosterlitz-Thouless vortices in superconductors immersed in an external magnetic field.
The Beresinskii-Kosterlitz-Thouless (BKT) physics of vortices in two-dimensional superconductors at finite magnetic field is investigated by means of a field-theoretical approach based on the sine-Gordon model. This description leads to a straightforward definition of the field-induced magnetization and shows that the persistence of nonlinear effects at low fields above the transition is a typical signature of the fast divergence of the correlation length within the BKT theory.
Benfatto
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Centro Studi e Ricerche Enrico Fermi, via Panisperna 89/A, I-00184, Rome, Italy.
Castellani
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C
Giamarchi
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