Phase coherence and the Nernst effect at magic angles in organic conductorsN. P. Ong, Weida Wu, P. M. Chaikin and P. W. Anderson
Department of Physics, Princeton University - Princeton, NJ 08544, USA
(Received 1 March 2004; accepted 17 March 2004)
A giant Nernst signal was recently observed for fields near crystallographic directions in . Such large Nernst signals are most naturally associated with the motion of pancake vortices. We propose a model in which phase coherence is destroyed throughout the sample except in planes closely aligned with the applied field H. A small tilt above or below the plane changes the direction and density of the penetrating vortices and leads to a Nernst signal that varies with the tilt angle of H as observed. The resistance notches at magic angles are understood in terms of flux-flow dissipation from field-induced vortices.
74.20.-z - Theories and models of superconducting state.
74.70.Kn - Organic superconductors.
72.15.Jf - Thermoelectric and thermomagnetic effects.
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