Indication for the coexistence of closed orbit and quantum interferometer with the same cross section in the organic metal (ET)4(H3O)[Fe(C2O4)3].C6H4Cl2: Persistence of SdH oscillations above 30 K
Abstract
Shubnikov-de Haas (SdH) and de Haas-van Alphen (dHvA) oscillations spectra of the quasi-two dimensional charge transfer salt β"-(ET)4(H3O)[Fe(C2O4)3]·C6H4Cl2 have been investigated in pulsed magnetic fields up to 54 T. The data reveal three basic frequencies Fa, Fb and Fb - a, which can be interpreted on the basis of three compensated closed orbits at low temperature. However a very weak thermal damping of the Fourier component Fb, with the highest amplitude, is evidenced for SdH spectra above about 6 K. As a result, magnetoresistance oscillations are observed at temperatures higher than 30 K. This feature, which is not observed for dHvA oscillations, is in line with quantum interference, pointing to a Fermi surface reconstruction in this compound.