PEIERLS INSTABILITY AND CHIRAL-SYMMETRY BREAKING IN SOLIDS WITH RELATIVISTIC FERMIONS

The Peierls instability for linear spectrum fermions is considered. It is shown that for a sufficiently strong fermion interaction a phase transition takes place, and the fermions become massive. This phenomenon is analogous to chiral symmetry breaking in 3+1 QED. The large-N approximation is applied. It is shown that in the weak-coupling limit fluctuations of the order parameter are strong and can lead to a first-order phase transition. In the strong-coupling limit, the phase transition is of the second type. The effect of anisotropy of the spectrum is discussed. © 1990 The American Physical Society.