Quantum-trajectory analysis for charge transfer in solid materials induced by strong laser fields

Abstract

We investigate the dependence of charge transfer on the intensity of driving laser field when SiO crystal is irradiated by an 800 nm laser. It is surprising that the direction of charge transfer undergoes a sudden reversal when the driving laser intensity exceeds critical values with different carrier-envelope phases. By applying quantum-trajectory analysis, we find that the Bloch oscillation plays an important role in charge transfer in solids. Also, we study the interaction of a strong laser with gallium nitride (GaN), which is widely used in optoelectronics. A pump-probe scheme is applied to control the quantum trajectories of the electrons in the conduction band. The signal of charge transfer is controlled successfully by means of a theoretically proposed approach.

Effect of transition dipole phase on high-order-harmonic generation in solid materials

“…When interacting with strong laser fields, the electrons would be driven away from the high-symmetry points and even travel through the entire Brillouin zone, thus the first-order k•p approximation is not appropriate. In our previous papers [21,24] and reference [29], the absolute values of the k-dependent TDMs are calculated from the density functional theory (DFT). However, based on the above analysis, ignoring the TDP is not justified for a system without symmetry.…”

“…Using the Bloch picture, there are two major mechanisms that contribute to the HHG process: the intraband current and the interband polarization. These two mechanisms have been used to interpret many experimental results successfully [1,3,9,10,[20][21][22][23]. Generally speaking, both mechanisms strongly depend on the band structure [1,3] of the solid and the nature of its transition dipole moment [24].…”

High-order-harmonic generation of a doped semiconductor

“…Therefore, it has potential to produce more efficient HHG than the gas [17]. By analyzing the spectrum of the solid HHG, it is possible to study the structures of solid materials [17][18][19][20]. The solid HHG can also provide a new path to investigate the attosecond electron dynamics in solid materials [21] and to reconstruct the energy-band structures of solid crystals [22].…”

Reciprocal-Space-Trajectory Perspective on High-Harmonic Generation in Solids

“…Although several numerical models, such as numerically solving the time-dependent Schödinger equation (TDSE) [20][21][22][23], the semiconductor Bloch equation (SBE) [24][25][26][27][28], and time-dependent density functional theory (TDDFT) [29,30] provide good descriptions of HHG, the underlying mechanisms are buried in the wave functions. Following the principle of HHG in gases [31], a generalized three-step model [26,32,33] has also been proposed for solids. In brief, near the peak of the laser field, the electron tunnels vertically from the valence band (VB) to the conduction band (CB).…”