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Anisotropy in the helicity modulus of a quantum 3D XY-model: application to YBCO

B. Mitrovic·K. Samokhin·S. K. Bose
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Abstract

We present a variational study of the helicity moduli of an anisotropic quantum three-dimensional (3D) XY-model of YBCO in superconducting state. It is found that both the ab-plane and the c-axis helicity moduli, which are proportional to the inverse square of the corresponding magnetic field penetration depth, vary with temperature T as T to the fourth power in the zero temperature limit. Moreover, the c-axis helicity modulus drops with temperature much faster than the ab-plane helicity modulus because of the weaker Josephson couplings along the c-axis compared to those along the ab-plane. These findings are in disagreement with the experiments on high quality samples of YBCO.

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B. Mitrovic, K. Samokhin, S. K. Bose. 2003-10-14. Anisotropy in the helicity modulus of a quantum 3D XY-model: application to YBCO. https://doi.org/10.1088/0953-8984%2F15%2F44%2F009

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