Single magnetic ions in semiconductor quantum dots

Single magnetic ion is the theoretical limit for miniaturization of magnetic memories. It is an interesting challenge to simultaneously write/read information in spin of such an ion. Due to strong ion-carrier intercoupling, such capabilities may appear for ions placed within semiconductor quantum dots. Purely spectroscopic techniques capable to access single objects might be applied due to excellent optical properties of the dots.

Type II-VI dots, in particular CdTe dots with Mn²⁺ ions, are convenient model systems to study quantum dots with single magnetic ions. Until recently CdTe:Mn and InAs:Mn dots were the only such systems available. However, a number of new material/ion pairs, including CdSe:Mn, CdTe:Co and CdSe:Fe, were recently obtained in Warsaw. We have also managed to show that the range of various semiconductor quantum dots with various magnetic ions may be further extended to include also materials, for which bandgap is wider than energies of centre-to-centre transitions in the magnetic ion.

Topics to be presented during the seminar include:

• methods to write/read information in magnetic ions within semiconductor quantum dots
• phenomena accompanying coherent evolution of a single magnetic ion and the dependence of spin relaxation time on magnetic field
• the most recent achievements in the technology of producing new type quantum dots.

All interested persons are invited
M. Kowal, W. Piechocki, L. Roszkowski, J. Skalski, L. Szymanowski