Transient dynamics of super Bloch oscillations of a 1D Holstein polaron under the influence of an external AC electric field

• Main Authors: Huang, Zhongkai, Hoshina, Masayuki, Ishihara, Hajime, Zhao, Yang
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Materials; Carrier–phonon Coupling; Davydov Ansatz
• Online Access: https://hdl.handle.net/10356/143657
• Institution: Nanyang Technological University

Theoretical formalism for DC‐field polaron dynamics is extended to the dynamics of a 1D Holstein polaron in an external AC electric field using multiple Davydov trial states. Effects of carrier–phonon coupling on detuned and resonant scenarios are investigated for both phase and nonzero phase. For slightly off‐resonant or detuned cases, a beat between the usual Bloch oscillations and an AC driving force results in super Bloch oscillations, that is, rescaled Bloch oscillations in both the spatial and the temporal dimension. Super Bloch oscillations are damped by carrier–phonon coupling. For resonant cases, if the carrier is created on two nearest‐neighboring sites, the carrier wave packet spreads with small‐amplitude oscillations. Adding carrier–phonon coupling localizes the carrier wave packet. If an initial broad Gaussian wave packet is adopted, the centroid of the carrier wave packet moves with a certain velocity and with its shape unchanged. Adding carrier–phonon coupling broadens the carrier wave packet and slows down the carrier movement. Our findings may help provide guiding principles on how to manipulate the dynamics of the super Bloch oscillations of carriers in semiconductor superlattice and optical lattices by modifying DC and AC field strengths, AC phases, and detuning parameters.