Photoinduced Kerr rotation spectroscopy for microscopic spin systems using heterodyne detection

We develop a transient photoinduced Kerr rotation spectroscopy technique using a heterodyne detection scheme to study spin dynamics of microscopic quantum states in solids, such as single quantum dots and spin helixes. The use of the heterodyne beat note signal generated by the interference of the frequency-shifted probe and reference pulses realizes the Kerr rotation measurements in combination with micro-spectroscopy, even when the probe pulse propagates collinearly with the strong pump pulse, which resonantly excites the probing state. In addition, the interference gives an optical amplification of the Kerr signal, which provides a clear observation of the photoinduced spin dynamics by the weak probe intensity. Here, we present results of Kerr rotation measurements for a single quantum dot exciton, which shows a maximum rotation angle of few mu rad. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

A transient photoinduced Kerr rotation spectroscopy technique was developed to study spin dynamics of microscopic quantum states in solids, with the use of heterodyne detection scheme. The results showed a maximum rotation angle of a few micro radians for a single quantum dot exciton. This technique allows for clear observation of photoinduced spin dynamics with weak probe intensity.