MAGNETIC-FIELD DEPENDENCE OF PHASE CORRELATION LENGTH IN SPIN-DENSITY AND CHARGE-DENSITY WAVES

Within a simple quasi-two-dimensional model, we study the phason propagator in both spin- and charge-density waves in the presence of a magnetic field perpendicular to the conducting plane. We find, though the magnetic field has little effect in the longitudinal correlation length (i.e., the correlation length in the chain direction), the magnetic field reduces significantly the transverse correlation length. This effect is most easily observable as increases in the fluctuation-induced specific heat and the resistivity in the chain direction in magnetic fields.