Magnetic ion relaxation time distribution within a quantum well

TL;DR

This study uses time-resolved ODMR to analyze how the relaxation times of magnetic Mn ions in quantum wells depend on their position and local environment, revealing potential for electric field control.

Contribution

It introduces selective Mn-doping in quantum wells to enhance the spatial resolution of ODMR and investigates the position-dependent spin relaxation of Mn ions.

Findings

Spin-lattice relaxation varies with Mn ion position within the quantum well.

Ion-carrier wavefunction overlap influences relaxation at low magnetic fields.

Potential for electric field control of Mn ion relaxation rates.

Abstract

Time-resolved optically detected magnetic resonance (ODMR) is a valuable technique to study the local deformation of the crystal lattice around magnetic ion as well as the ion spin relaxation time. Here we utilize selective Mn-doping to additionally enhance the inherent locality of the ODMR technique. We present the time-resolved ODMR studies of single {(Cd,Mg)Te/(Cd,Mn)Te} quantum wells (QWs) with manganese ions located at different positions along the growth axis -- in the center or on the sides of the quantum well. We observe that spin-lattice relaxation of Mn$^{2+}$ significantly depends on the ion-carrier wavefunction overlap at low-magnetic fields. Interestingly, the effect is clearly observed in spite of very low carrier density, which suggests the potential for control of the Mn$^{2+}$ ion relaxation rate by means of the electric field in future experiments.