Anomalous Magnetization Exponent and Singular Frustration Induced Gap inIncommensurate Massive One-Dimensional Lattice Models

摘要

This paper investigates the frustration induced phenomena at the commensurate-incommensurate crossing point in one-dimensional massive systems. The massive elementary excitation can be described by a dispersion e(k )=√∑ an cos(nk), with a set of phenomenological coefficients an, which depend on the frustration. From the dispersion,we find that at the commensurate-incommensurate crossing point, both pitch angle and the correlation length have square root singularities, being functions of funstration intensity. The gap in the incommensurate side also comes to be singular while approaching the crossing point. Anomalous magnetization exponent appears at the singular point of the spin gap.