J. Phys. IV France 10 (2000) Pr3-127-Pr3-137
Are there stripes in the ET materials ?V.J. Emery1 and S.A. Kivelson2
1 Brookhaven National Laboratory, Upton, NY 11973-5000, U.S.A.
2 Department of Physics, UCLA, Los Angeles, CA 90095, U.S.A.
We propose that a central aspect of two-dimensional doped antiferromagnets, including the cuprate high temperature superconductors and the (BEDT-TTF)2X materials, is a "dynamical dimension reduction" in which the electrons self-organise in a quasi one-dimensional manner. Strong repulsive interactions between electrons frustrate their motion, resulting in a large zero-point kinetic energy. As a function of decreasing temperature, this kinetic energy is lowered in three steps that are reflected in a sequence of crossovers and phase transitions : first of all, the system develops a charge-inhomogeneous state - an array of one-dimensional metallic stripes that forms an electronic liquid crystal ; this lowers the kinetic energy along a stripe. In the transverse direction in the planes, the kinetic energy is lowered by pair hopping, which first creates spin pairs and then, at a lower temperature, superconducting phase coherence. This constitutes a new mechanism and many-body theory of superconductivity. Evidence for this behaviour in the high temperature superconductors, and implications of the conjecture that similar behaviour occurs in the (BEDT-TTF)2X materials are described.
© EDP Sciences 2000