Sliding phase in randomly stacked 2d superfluids/superconductors
Laboratoire de Physique Théorique, Université de Toulouse, UPS (IRSAMC) - F-31062 Toulouse, France, EU
Received: 30 May 2012
Accepted: 16 August 2012
Using large-scale quantum Monte Carlo simulations of lattice bosonic models, we precisely investigate the effect of weak Josephson tunneling between 2D superfluid or superconducting layers. In the clean case, the Kosterlitz-Thouless transition immediately turns into 3DXY, with phase coherence and superflow in all spatial directions, and a strong enhancement of the critical temperature. However, when disorder is present, rare regions fluctuations can lead to an intermediate finite-temperature phase —the so-called sliding regime— where only 2D superflow occurs within the layers without any transverse superfluid coherence, while a true 3D Bose-Einstein condensate exists. Critical properties of such an unconventional regime are carefully investigated.
PACS: 61.43.Bn – Structural modeling: serial-addition models, computer simulation / 67.25.dj – Superfluid transition and critical phenomena / 74.62.En – Effects of disorder
© EPLA, 2012