J. Phys. I France 6 (1996) 1819-1936
Magnetic Oscillations in a Normal State of Organic Conductors: Many-Body ApproachA.G. Lebed
Institute for Materials Research, Tohoku University, Sendai 980-77, Japan and L.D. Landau Institute for Theoretical Physics, Russian Academy of Sciences, 117334 Moscow, 2 Kosygina St., Russia
(Received 26 April 1996, received in final form 27 June 1996, accepted 4 July 1996)
We argue that magnetic and angular oscillations observed in quasi-one-dimensional (Q1D) organic conductors represent a new type of many-body phenomena. The physical nature of such effects as "magic angles" in (TMTSF) 2ClO 4, (TMTSF) 2PF 6, and (DMET-TSeF) 2 AuCl 2 as well as "rapid magnetic oscillations" in (TMTSF) 2ClO 4 is shown to be beyond the standard theory of metals. Below we discuss an explanation of these phenomena which utilizes unusual many-body effect - a change of an effective dimensionality of electron-electron ("e-e") interactions with changing both a magnitude and a direction of a magnetic field. We show that some exotic transport properties of a metallic state can be interpreted in terms of these dimensional crossovers. We also demonstrate that magnetic field dependence of "e-e" interactions has to break Fermi liquid description of quasiparticles at high magnetic fields, T. This leads to the appearance of strong forbidden oscillations of magnetic susceptibility, and magnetic moment, All of the above mentioned unique properties of a metallic phase in (TMTSF) 2X and (DMET-TSeF)AuCl 2 allow us to call it an anomalous metallic phase.
© Les Editions de Physique 1996