title: Fast, Accurate Simulation of Polaron Dynamics and Multidimensional Spectroscopy by Multiple Davydov Trial States.
abstract: By employing the Dirac-Frenkel time-dependent variational principle, we study the dynamical properties of the Holstein molecular crystal model with diagonal and off-diagonal exciton-phonon coupling. A linear combination of the Davydov D1 (D2) ansatz, referred to as the "multi-D1 ansatz" ("multi-D2 ansatz"), is used as the trial state with enhanced accuracy but without sacrificing efficiency. The time evolution of the exciton probability is found to be in perfect agreement with that of the hierarchy equations of motion, demonstrating the promise the multiple Davydov trial states hold as an efficient, robust description of dynamics of complex quantum systems. In addition to the linear absorption spectra computed for both diagonal and off-diagonal cases, for the first time, 2D spectra have been calculated for systems with off-diagonal exciton-phonon coupling by employing the multiple D2 ansatz to compute the nonlinear response function, testifying to the great potential of the multiple D2 ansatz for fast, accurate implementation of multidimensional spectroscopy. It is found that the signal exhibits a single peak for weak off-diagonal coupling, while a vibronic multipeak structure appears for strong off-diagonal coupling.
authors.affiliation: Department of Physics, Hangzhou Normal University , Hangzhou 310046, China.|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: Lipeng
authors.initials: L
authors.lastname: Chen
authors.affiliation: Division of Materials Science, Nanyang Technological University , Singapore 639798, Singapore.
authors.forename: Zhongkai
authors.initials: Z
authors.lastname: Huang
authors.affiliation: School of Science, Hangzhou Dianzi University , Hangzhou 310046, China.
authors.forename: Kewei
authors.initials: K
authors.lastname: Sun
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University , Kyoto 606-8502, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tanimura
authors.affiliation: Division of Materials Science, Nanyang Technological University , Singapore 639798, Singapore.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao