arXiv subjects

Adam Gindl

Publications and source records attributed to Adam Gindl.

3 recordsLinked to original sources

arXiv2026

Coherent electronic Raman excitation of valley-orbit split states of phosphorus dopants in silicon

In this study, we demonstrate coherent optical excitation of the electronic Raman transition between the $1s\left(A_1\right)$ and $1s\left(E\right)$ split states of phosphorus donor in crystalline silicon. The dynamics of the generated wavepacket is characterized in the time domain using a degenerate pump-probe technique with mid-infrared femtosecond pulses via transient polarization anisotropy of the probe pulse. In addition, we study the role of resonantly excited carriers, and we show that the amplitude and coherence time of the electronic wavepacket depend on the pre-excited carrier density. Further, we demonstrate that under certain conditions, the Raman-type excitation changes to displacive impulsive excitation, which allows us to address the Raman-forbidden transition between $1s\left(A_1\right)$ and $1s\left(T_1\right)$.

cond-mat.mes-hall↗

arXiv2024

Ultrafast room-temperature valley manipulation in silicon and diamond

Some semiconductors have more than one degenerate minimum of the conduction band in their band structure. These minima-known as valleys-can be used for storing and processing information, if it is possible to generate a difference in their electron populations. However, to compete with conventional electronics, it is necessary to develop universal and fast methods for controlling and reading the valley quantum number of the electrons. Even though selective optical manipulation of electron populations in inequivalent valleys has been demonstrated in two-dimensional crystals with broken time-reversal symmetry, such control is highly desired in many technologically important semiconductor materials, including silicon and diamond. We demonstrate an ultrafast technique for the generation and read-out of a valley-polarized population of electrons in bulk semiconductors on subpicosecond timescales. The principle is based on the unidirectional intervalley scattering of electrons accelerated by an oscillating electric field of linearly polarized infrared femtosecond pulses. Our results are an advance in the development of potential room-temperature valleytronic devices operating at terahertz frequencies and compatible with contemporary silicon-based technology.

cond-mat.mes-hall↗

arXiv2023

Attosecond control of solid-state high harmonic generation using {\omega}-3{\omega} fields

High harmonic spectra generated in condensed matter carry the fingerprints of sub-cycle electronic motion and the energy structure of the studied system. Here we show that tailoring the waveform of mid-infrared driving light by using a coherent combination with its third harmonic frequency allows to control the time of electron tunneling to the conduction band within each half-cycle of the fundamental wave with attosecond precision. We introduce an experimental scheme in which we simultaneously monitor the modulation of amplitude and emission delays of high harmonic radiation and the excited electron population generated in crystalline silicon as a function of the relative phase between the $\omega$-3$\omega$ fields. We observe that the mutual $\omega$-3$\omega$ phase required for the maximum yield of high harmonic generation is shifted by approximately $\pi/2$ with respect to the phase leading to maximal generated carrier population. The observed emission delays of high harmonic photons of up to few hundred attoseconds scale with the time delay and with the ratio between the electric field amplitudes of the two-color fields. These results reveal the connection between electron tunneling and high harmonic emission processes in solids.

physics.optics↗