Damped Rabi wavepacket oscillations and damping time in correlated random ladders

• The electronic wavepacket dynamic in a ladder with correlated disorder is studied.
• We show that the wavepacket width develops damped Rabi-like oscillations.
• We observe weak localization for antisymmetric cross-correlations.
• Damped Rabi-like oscillation is observed after the wavepacket reaches the borders.
• The Damped Rabi-like oscillation is absent in the strong localization regime.

In this work, we follow the time evolution of an initially localized one-electron wavepacket in a random ladder model with correlated diagonal disorder. Weak localization of the eigenstates is anticipated for antisymmetric cross-correlations with every base pair having the same average energy. We show that the wavepacket width develops damped Rabi-like oscillations after reaching the ladder's borders. The Rabi-like oscillations are shown to originate from the interference between neighboring energy eigenstates, while its damping is associated with a destructive interference due to the random scattering in the underlying random potential. The typical damping time td is estimated as a function of the ladder size N   and shown to increase as td∝Nztd∝Nz with z=0.62(4)z=0.62(4). The strong localization in the absence of antisymmetric cross-correlations suppresses the oscillations.

Time-evolution of the mean-squared displacement of a wavepacket for ladders of different sizes. The statistically stationary regime is reached after damped Rabi-like oscillations.Figure optionsDownload as PowerPoint slide