Spectral properties of the 2D Holstein t-J model

SPECTRAL PROPERTIES OF THE 2D HOLSTEIN t–J MODEL

Employing the Lanczos algorithm in combination with a kernel polynomial moment expansion (KPM) and the maximum entropy method (MEM), we show a way of calculating charge and spin excitations in the Holstein t–J model, including the full quantum nature of phonons. To analyze polaron band formation we evaluate the hole spectral function for a wide range of electron–phonon coupling strengths. For t...

Polaronic features in the optical properties of the Holstein t-J model

Spectral properties of the t-J model in the presence of hole-phonon interaction.

We examine the effects of electron-phonon interaction on the dynamics of the charge carriers doped in two-dimensional (2D) Heisenberg antiferromagnet. The t-J model Hamiltonian with a Fröhlich term which couples the holes to a dispersionless (optical) phonon mode is considered for low doping concentration. The evolution of the spectral density function, the density of states, and the momentum d...

Polaronic effects in strongly coupled electron-phonon systems: Exact diagonalization results for the 2D Holstein t–J model

Ground–state and dynamical properties of the 2D Holstein t–J model are examined by means of direct Lanczos diagonalization, using a truncation method of the phononic Hilbert space. The single– hole spectral function shows the formation of a narrow hole–polaron band as the electron–phonon coupling increases, where the polaronic band collapse is favoured by strong Coulomb correlations. In the two...

Spectral functions of the spinless Holstein model

An analytical approach to the one-dimensional spinless Holstein model is proposed, which is valid at finite charge-carrier concentrations. Spectral functions of charge carriers are computed on the basis of self-energy calculations. A generalization of the Lang-Firsov canonical transformation method is shown to provide an interpolation scheme between the extreme weak– and strong-coupling cases. ...