Low-energy photoexcitations inside the Mott gap in doped Hubbard and t-J ladders

Abstract

We investigate changes in the optical conductivity of doped Mott insulators by tuning ultrashort pump pulses to target either the Drude or low-energy absorption regions. Using a hole-doped two-leg Hubbard ladder and a four-leg t-J ladders, we calculate the optical conductivity after pump by employing the time-dependent density matrix renormalization group. We find that a monocycle electric field pulse tuned to the Drude absorption reduces the Drude weight, accompanied by a slight enhancement in the mid-infrared (mid-IR) spectral weight. However, this enhancement diminishes as the pulse intensity increases. In contrast, a pump pulse tuned to the mid-IR absorption only affects the Drude weight. This behavior arises because the mid-IR absorption originates from magnetic excitations that do not couple directly to photons. These predictions can be tested experimentally by applying ultrashort low-energy pump pulses to cuprate materials.

7 pages, 5 figures

References in corpus (12)

• Charge dynamics of doped holes in high Tc cuprates - A clue from optical conductivity
• Exact diagonalization study of optical conductivity in two-dimensional Hubbard model
• Photoinduced in-gap excitations in the one-dimensional extended Hubbard model
• Robust superconducting correlation against inter-site interactions in the extended two-leg Hubbard ladder
• Reexamining doped two-legged Hubbard ladders
• Density-matrix renormalization group study of optical conductivity of the Mott insulator for two-dimensional clusters
• Optical conductivity in the t-J-Holstein Model
• Glassy dynamics of the one-dimensional Mott insulator excited by a strong terahertz pulse
• Anomalous suppression of photo-induced in-gap weight in the optical conductivity of a two-leg Hubbard ladder
• Spin Dynamics in the t-t'-J Model: Dynamical Density-Matrix Renormalization Group Study
• Dynamics of non-thermal states in optimally-doped $B{i}_{2}S{r}_{2}C{a}_{0.92}{Y}_{0.08}C{u}_2{O}_{8+\delta }$ revealed by mid-infrared three-pulse spectroscopy
• Optical absorption activated by an ultrashort half-cycle pulse in metallic and superconducting states of the Hubbard model