All-optically induced ultrafast photocurrents: Beyond the instantaneous coherent response

Abstract

It is demonstrated that the non-instantaneous response of the optically induced coherent polarization tremendously influences the real-space shift of electronic charges in semiconductors. The possibility to coherently control this real-space shift with temporally non-overlapping excitation pulses allows for the observation of a new type of shift current, which only exists for certain polarization-shaped excitation pulses and vanishes in the continuous-wave limit. In contrast to previously studied shift currents, the new current requires a phase mismatch between two orthogonal transition dipole moments and leads, within a nonlinear second-order description, to a tensor which is antisymmetric with respect to the order of the two exciting electric field amplitudes. These observations, which can even be made at room temperature and are expected to occur in a variety of semiconductor crystal classes, contribute to a better understanding of light-matter interaction involving degenerate bands. Thus, they are expected to prove important for future studies of coherent and nonlinear optical effects in semiconductors.

References in corpus (1)

• Observation of second-harmonic generation induced by pure spin currents

Cited by in corpus (8)

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• High-frequency nonlinear transport and photogalvanic effects in two-dimensional topological insulators
• Detection of the anomalous velocity with sub-picosecond time resolution in semiconductor nanostructures
• A non-perturbative study of bulk photovoltaic effect enhanced by an optically induced phase transition
• All-optically induced currents resulting from frequency modulated coherent polarization
• Excitation of spin density and current by coherent light pulses in QWs