Transverse and in-plane modification of superconductivity and electronic structure in the quasi-two-dimensional organic conductor kappa-(BEDT-TTF)(2)Cu(SCN)(2) by uniaxial stress
Es. Choi et al., Transverse and in-plane modification of superconductivity and electronic structure in the quasi-two-dimensional organic conductor kappa-(BEDT-TTF)(2)Cu(SCN)(2) by uniaxial stress, PHIL MAG B, 81(4), 2001, pp. 399-416
We have employed uniaxial stress along the principal axes of the quasi-two-
dimensional organic superconductor kappa-(BEDT-TTF)(2)Cu(SCN)(2) (BEDT-TTF
= bis(ethylenedithio)tetrathiafulvalene). The lattice anisotropy is there b
y altered, with corresponding changes in the intermolecular transfer energi
es. The effect of uniaxial stress on the superconducting transition tempera
ture T-c and critical field B-c2 is found to be anisotropic. There is an in
dication of an increase in T-c and an increase in B-c2 for in-plane stress,
but both parameters decrease rapidly for transverse (interplane) stress. M
agnetotransport studies reveal stress-induced changes in the Fermi surface
through the observation of the Shubnikov-de Haas oscillations. The stress d
ependence of a resistive anomaly in the magnetoresistance, which is associa
ted with the critical field B-c2 is also investigated. We discuss the exper
imental findings in the context of recent phenomenological and theoretical
treatments of quasi-two-dimensional systems where the anisotropic triangula
r-lattice Hubbard model has been used to treat two-dimensional superconduct
ors.