Pekker, DavidRefael, GilDemler, Eugene2014-11-242010Pekker, David, Gil Refael, and Eugene A. Demler. 2010. Finding the elusive sliding phase in the superfluid-normal phase transition smeared by \(c\)-axis disorder. Physical Review Letters 105(8): 085302.0031-90071079-7114http://nrs.harvard.edu/urn-3:HUL.InstRepos:13421137We consider a stack of weakly Josephson coupled superfluid layers with \(c\)-axis disorder in the form of random superfluid stiffnesses and vortex fugacities in each layer as well as random interlayer coupling strengths. In the absence of disorder this system has a 3D \(XY\) type superfluid-normal phase transition as a function of temperature. We develop a functional renormalization group to treat the effects of disorder, and demonstrate that the disorder results in the smearing of the superfluid-normal phase transition via the formation of a Griffiths phase. Remarkably, in the Griffiths phase, the emergent power-law distribution of the interlayer couplings gives rise to a sliding Griffiths superfluid, with a finite stiffness in the \(a-b\) direction along the layers, and a vanishing stiffness perpendicular to it.en-USquantum gasesJournal Article2014-11-2410.1103/PhysRevLett.105.085302