1205.5518 (Jie Yong et al.)

Evidence of Two-Dimensional Quantum Critical Behavior in the Superfluid
Density of Deeply Underdoped Bi2Sr2CaCu2O8+x    [PDF]

Jie Yong, M. J. Hinton, A. McCray, M. Randeria, M. Naamneh, A. Kanigel, T. R. Lemberger

Evidence of two-dimensional (2D) quantum critical fluctuations is observed in the superfluid density ns(T) \propto $\lambda$ -2(T) of deeply underdoped Bi2Sr2CaCu2O8+x (Bi-2212) films, indicating that quantum fluctuations play a dominant role in underdoped cuprates in general. 2D fluctuations are expressed by the linear scaling, Tc \propto ns(0). 2D scaling in Bi-2212 contrasts with 3D scaling seen in the much less anisotropic YBa2Cu3O7-x. Quantum critical fluctuations could also account for the absence of thermal critical behavior in \lambda^{-2}(T) of strongly underdoped Bi-2212 samples, Tc < 48 K.

View original: http://arxiv.org/abs/1205.5518