The widths of single-particle states of anisotropic, strongly correlated electron systems in solids

The damping γ(ε) of electron states in crystals is investigated beyond the phase transition point related to a rearrangement of the Fermi surface. Attention is focused on the alteration of the standard Landau theory due to the emergence of a flat portion in the spectrum ξ(p) of single-particle excitations as a result of the rearrangement. In the limit ε →0, the width γ(ε) of the states in the region of the Brillouin zone where the dispersion of ξ(p) is of an ordinary order of magnitude is found to depend on ε almost linearly, in contrast to the Fermi-liquid-theory result γ(ε)∼ε². Pis’ma Zh. éksp. Teor. Fiz. 70, No. 11, 759–765 (10 December 1999) Published in English in the original Russian journal. Edited by Steve Torstveit.