Transfer-matrix method for non-Hermitian pseudo-Hamiltonians and the commensurate-incommensurate charge-density-wave transition

A microscopic commensurability pinning Hamiltonian with charge conservation is presented and analyzed as a model for the commensurate-incommensurate charge-density-wave transition. The ground state is always a soliton lattice with its character changing continuously between commensurate and incommensurate states depending on the commensurability strength. The existing transfer-matrix methods are criticized and extended to non-Hermitian pseudo-Hamiltonian systems. Charge conservation leads to results for the charge-density correlation length and the structure factor that are consistent with the x-ray-scattering experiment and the NMR Knight-shift experiment on 2H-TaSe₂.