Competition between Josephson and electromagnetic interactions in $ Bi_2Sr_2CaCu_2O_8$ single crystals

Sudershany, YS and Rastogiy, A and Bhat, SV and Groverz, AK and Yamaguchi, Y and Oka, K and Nishihara, Y (1998) Competition between Josephson and electromagnetic interactions in $ Bi_2Sr_2CaCu_2O_8$ single crystals. In: Superconductor Science and Technology, 11 (12). pp. 1372-1380.

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Abstract

We have studied the low magnetic field, high-temperature region of the H-T phase diagram of Bi2Sr2CaCu2O8 (Bi2212) single crystals by measuring magnetic field (H parallel to c) induced rf (H-rf parallel to a) dissipation in the mixed state. Normally the rf power loss P(H) versus H in a superconductor increases with the increase in the field with a minimum at H = 0. However. in Bi2212 the rf loss initially decreases with increasing field, shows a minimum at a certain field H-M > 0 and increases continuously beyond H-M. We understand the unusual minimum at H-M as resulting from a competition between (i) the increasing attractive electromagnetic interaction between the pancake vortices (that constitute the vortex line) in adjacent bilayers with the increasing field and (ii) the decreasing Josephson coupling between the CuO bilayers with the increase in the field. The H-M(T) line defines a new boundary in the H-T phase diagram at which the tilt modulus C-44 Of the 2D vortex stack in Bi2212 is at a maximum. It is found to obey the (1 - t(2))(n) behaviour with the exponent n = 3/2 reminiscent of the predicted behaviour of the melting line.

Item Type:	Journal Article
Publication:	Superconductor Science and Technology
Publisher:	Institute of Physics
Additional Information:	Copyright of this article belongs to Institute of Physics.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	28 May 2009 10:53
Last Modified:	19 Sep 2010 05:01
URI:	http://eprints.iisc.ac.in/id/eprint/18296

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