Yc. Jean et al., MOMENTUM DISTRIBUTION IN KAPPA-(BEDT-TTF)2CU[N(CN)2]BR ORGANIC SUPERCONDUCTOR MEASURED BY POSITRON-ANNIHILATION - SEARCH FOR THE FERMI-SURFACE, Physica. C, Superconductivity, 221(3-4), 1994, pp. 399-404
We report the first precise measurement of the positron-electron momen
tum distribution in an organic superconducting single crystal kappa-(B
EDT-TTF)2Cu[N(CN)2] Br by the 2D-ACAR method. The anisotropy in the ra
w spectrum has the appropriate symmetry and is consistent with the str
ucture factors of the space group of the crystal. The LCW-folded k-spa
ce density is discussed and compared with the Fermi surface prediction
of a HMO calculation. Substantial discrepancies between the experimen
tal results and the existing theory are found.