title: Polaron dynamics with a multitude of Davydov D2 trial states.
abstract: We propose an extension to the Davydov D2 Ansatz in the dynamics study of the Holstein molecular crystal model with diagonal and off-diagonal exciton-phonon coupling using the Dirac-Frenkel time-dependent variational principle. The new trial state by the name of the "multi-D2 Ansatz" is a linear combination of Davydov D2 trial states, and its validity is carefully examined by quantifying how faithfully it follows the Schrödinger equation. Considerable improvements in accuracy have been demonstrated in comparison with the usual Davydov trial states, i.e., the single D1 and D2 Ansätze. With an increase in the number of the Davydov D2 trial states in the multi-D2 Ansatz, deviation from the exact Schrödinger dynamics is gradually diminished, leading to a numerically exact solution to the Schrödinger equation.
authors.affiliation: Division of Materials Science, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Nengji
authors.initials: N
authors.lastname: Zhou
authors.affiliation: Division of Materials Science, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Zhongkai
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Division of Materials Science, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Jiangfeng
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Division of Materials Science, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Chernyak
authors.affiliation: Division of Materials Science, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao