title: Study of the one-dimensional Holstein model with next-nearest-neighbor hopping.
abstract: We present the effect of next-nearest-neighbor hopping on Holstein polarons. The energy and wavefunction of the ground state and first excited state are obtained by using a conjugate-gradient technique on the variational Hilbert space of the electron-phonon (e-ph) system. We increase the size of the variational space systematically to obtain high accuracy. With the converged wavefunction at our disposal we obtain various physical quantities and correlation functions to get a holistic insight into the physics of e-ph interaction. Our study reveals that the effect of next-nearest-neighbor hopping is most prominent at the physically interesting crossover regime of the e-ph coupling and in the adiabatic regime. We have also performed analytical strong coupling second order perturbation with a Lang-Firsov (LF) phonon basis to account for some features in the strong coupling regime.
authors.affiliation: Theoretical Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, India.
authors.forename: Monodeep
authors.initials: M
authors.lastname: Chakraborty
authors.forename: A N
authors.initials: AN
authors.lastname: Das
authors.forename: Atisdipankar
authors.initials: A
authors.lastname: Chakrabarti
mesh_terms: D004583:Electrons; D015233:Models, Statistical; D013816:Thermodynamics