Fermi surface reconstruction in (BEDT-TTF)/sub 2/TlH/sub g/(SCN)/sub 4/

Summary form only given. The Shubnikov-de Haas (SdH) measurements in the organic conductor, (BEDT-TTF)/sub 2/TlH/sub g/(SCN)/sub 4/ have been performed to clarify the Fermi surface. At 50mK, in addition to the oscillations which come from the closed orbit and the magnetic breakdown orbit in the original Fermi surface, at least eight SdH oscillations with different frequencies are observed for H //b/sup */-axis. All the frequencies are found to follow the 1/cos(/spl theta/) dependence, where /spl theta/ is the angle between the magnetic field and the b/sup */-axis. The results are understood by the reconstructsion of the Fermi surface due to the nesting.