Probing and Controlling the Spin State of Single Magnetic Atoms in an Individual Quantum Dot

Publisher Summary This chapter reviews that when magneto-electronic devices scales down, it becomes increasingly important to understand the properties of a single magnetic atom in a solid-state environment. Atomic scale surface probes are successfully used in this regard. More recently, optical probing of both magnetic and non-magnetic atoms in semiconductors is demonstrated. Magnetically doped semiconductors are used in the fabrication of electrically active devices that control the magnetic properties such as transition temperature and coercitive field. In these devices, a macroscopic number of magnetic atoms was manipulated. It presents here electrically active devices that control the charge state of an individual II–VI quantum dot (QD) doped with a single Mn atom. Quantum dots doped with magnetic atoms and filled with a tunable number of carriers can behave like tunable nanomagnets. The chapter also focuses on the observation of an individual spin in a QD that opens new possibilities in information storage. The spin of an isolated Mn atom should present a relaxation time in the millisecond range. This property could be exploited to store digital information on a single atom.