Optical signals of spin switching using the optical Stark effect in a Mn doped quantum dot

TL;DR

This paper explores how the optical Stark effect can control and monitor spin switching in a Mn-doped quantum dot, revealing detailed spin dynamics through time-resolved spectroscopy.

Contribution

It demonstrates a theoretical method to observe and enhance spin flips in a Mn quantum dot using the optical Stark effect and spectral analysis.

Findings

Optical Stark effect can bring spin flip states into resonance.

Spectral lines split into six, each representing Mn spin states.

Time-dependent spectral shifts reveal spin dynamics.

Abstract

The optically induced spin dynamics of a single Mn atom embedded into a single semiconductor quantum dot can be strongly influenced by using the optical Stark effect. The exchange interaction gives rise to simultaneous spin flips between the quantum dot electron and Mn. In the time domain these flips correspond to exchange induced Rabi oscillations, which are typically off-resonant. By applying a detuned laser pulse, the states involved in the flipping can be brought into resonance by means of the optical Stark effect increasing the amplitude of the Rabi oscillations to one. In this paper we study theoretically how this spin dynamics can be monitored in time-resolved spectroscopy. In the spectrum the exchange interaction leads to a splitting of the exciton line into six lines, each corresponding to one of the six Mn spin states. The dynamical behavior of the Mn spin is reflected by the strength of the individual lines as a function of time. When an off-resonant optical pulse is applied the spectral positions of the lines shift, but still the flipping dynamics is visible.