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Novel anisotropy in the superconducting gap structure of Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} probed by quasiparticle heat transport

Yoichi Ando·J. Takeya·Yasushi Abe·X. F. Sun·A. N. Lavrov
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Abstract

Since the nature of pairing interactions is manifested in the superconducting gap symmetry, the exact gap structure, particularly any deviation from the simple d_{x^2-y^2} symmetry, would help elucidating the pairing mechanism in high-T_c cuprates. Anisotropic heat transport measurement in Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} (Bi-2212) reveals that the quasiparticle populations are different for the two nodal directions and thus the gap structure must be uniquely anisotropic, suggesting that pairing is governed by interactions with a rather complicated anisotropy. Intriguingly, it is found that the "plateau" in the magnetic-field dependence of the thermal conductivity is observed only in the b-axis transport.

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Yoichi Ando, J. Takeya, Yasushi Abe, X. F. Sun, A. N. Lavrov. 2002-03-06. Novel anisotropy in the superconducting gap structure of Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} probed by quasiparticle heat transport. https://doi.org/10.1103/physrevlett.88.147004

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