Coherent Optical Control of the Ultrafast Dephasing of Phonon-Plasmon Coupling in a Polar Semiconductor Using a Pulse Train of Below-Band-Gap Excitation

Control of carrier transport in GaAs by longitudinal-optical phonon-carrier scattering using a pair of laser pump pulses

“…23 In this paper, we report experimentally on the coherent control of the relaxation time of the plasma-relevant coherent LO phonon-plasmon coupled mode using a femtosecond pump-pulse pair in n-GaAs under nearly below-gap excitation condition. The relaxation time of the plasma-relevant LOPC mode is directly linked to the carrier transport, 12,16,17 and therefore, our results are suggestive to a possibility of realization of near-ballistic regime as a consequence of the reduction of the electron-phonon scattering.…”

“…[13][14][15] One can enhance the amplitude of a phonon mode by applying in-phase pulses, or suppress it by applying out-of-phase pulses, both of which are observed in real time-domain. Recently, it has been theoretically pointed out that coherent control of relaxation of carrier plasma is possible by the irradiation of THz-rate trains of laser pulses with below-gap excitation condition, 16,17 while most of the pump-probe experiments and time-domain simulations have been made with above-gap excitation in GaAs, 7,[18][19][20][21][22] where the pump-pulse generates substantial nonequilibrium carriers in the conduction band with excess energy. In this condition, one expects that the firstly generated coherent LOPC modes may be always suppressed by the secondly pump-pulse if the separation time between the pump-pulses is several hundred femtoseconds.…”

Ultrafast optical excitation of coherent phonons in a one-dimensional metal at the photoinduced insulator-metal transition

“…1,2 According to an advancement of the femtosecond (fs) laser technology, an optical pumping with a shorter pulsed laser than a phonon period was found to lead to the coherent oscillation (i.e., coherent phonons) in the optical properties such as reflectivity or transmission. 3 Coherent phonons drive abundant physics such as many-body interferences singular at the onset of quasiparticle, 4,5 or possibilities for controlling coupled degrees of freedom in the ultrafast time span in semiconductors [6][7][8] and superconductors. 9 Generation of coherent phonons is also observed in a broad class of the photoinduced insulator-metal transitions (PIMTs) accompanying the structural changes in terms of the melting of the lattice-induced order.…”

Controlling the photoluminescence of gallium arsenide with trains of ultrashort laser pulses

“…3 To control reactions at high temperatures and/or densities, it is necessary either to complete the process before decoherence sets in or to design control schemes that suppress decoherence. 4,5 The effect of decoherence is especially severe in the solid state, where dephasing occurs typically in a few picoseconds. Previous experiments with solid materials used quantum interference to control carrier populations, 6 electron flow, 7 and coherent phonon oscillation 8 in semiconductors, as well as photoemission of electrons from metal surfaces.…”