Non-Fermi-Liquid Crossovers in a Quasi-One-Dimensional Conductor in a Tilted Magnetic Field.

We consider a theoretical problem of electron-electron scattering time in a quasi-one-dimensional (Q1D) conductor in a magnetic field, perpendicular to its conducting axis. We show that inverse electron-electron scattering time becomes of the order of characteristic electron energy, 1/τ~ε~T, in a high magnetic field, directed far from the main crystallographic axes, which indicates breakdown of the Fermi-liquid theory. In a magnetic field, directed close to one of the main crystallographic axis, inverse electron-electron scattering time becomes much smaller than characteristic electron energy and, thus, applicability of Fermi-liquid theory restores. We suggest that there exist crossovers (or phase transitions) between Fermi-liquid and some non-Fermi-liquid states in a strong enough tilted magnetic field. Application of our results to the Q1D conductor (Per)_{2}Au(mnt)_{2} shows that it has to be possible to observe the above-mentioned phenomenon in feasibly high magnetic fields of the order of H≥H^{*}≃25 T.