Josephson effect in the cuprates: microscopic implications
نویسنده
چکیده
In the tunnel limit, the current-phase relation of Josephson junctions can be expanded as I(φ) = I1 sinφ + I2 sin 2φ. Standard BCS theory predicts that I1RN ∼ ∆/e and I2/I1 ∼ D, where RN is the resistance of the junction in the normal state, ∆ is the superconducting gap, and D ≪ 1 is the junction transparency. In the cuprates, the experimental value of I1RN (I2/I1) is much smaller (larger) than the BCS prediction. We argue that both peculiarities of the cuprates can be explained by postulating quantum fluctuations of the pairing symmetry.
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