Doping dependence of the vortex-core energy in bilayer films of cuprates

Abstract

The energy needed to create a vortex core is the basic ingredient to address the physics of thermal vortex fluctuations in underdoped cuprates. Here we theoretically investigate its role on the occurrence of the Beresinskii-Kosterlitz-Thouless transition in a bilayer film with inhomogeneity. From the comparison with recent measurements of the penetration depth in two-unit cell thin films of Y${}_{1-x}$Ca${}_x$Ba${}_2$Cu${}_3$O$_{7-\d}$ (YBCO) by Hetel et al. [Nat. Phys. 3, 700 (2007)] we can extract the value of the vortex-core energy $\mu$, and show that $\mu$ scales linearly with $T_c$ at low doping.

4pages, 3 figures. References added, final version

References in corpus (4)

• Visualizing pair formation on the atomic scale in the high-Tc superconductor Bi2Sr2CaCu2O8+d
• Quantum critical behaviour in the superfluid density of strongly underdoped ultrathin cuprate films
• Sine-Gordon description of Beresinskii-Kosterlitz-Thouless physics at finite magnetic field
• Competition between Vortex Unbinding and Tunneling in an Optical Lattice