Myers R C, Mikkelsen M H, Tang J-M, Gossard A C, Flatté M E, Awschalom D D
Center for Spintronics and Quantum Computation, University of California, Santa Barbara, California 93106, USA.
Nat Mater. 2008 Mar;7(3):203-8. doi: 10.1038/nmat2123. Epub 2008 Feb 17.
Controlling and monitoring individual spins is desirable for building spin-based devices, as well as implementing quantum information processing schemes. As with trapped ions in cold gases, magnetic ions trapped on a semiconductor lattice have uniform properties and relatively long spin lifetimes. Furthermore, diluted magnetic moments in semiconductors can be strongly coupled to the surrounding host, permitting optical or electrical spin manipulation. Here we describe the zero-field optical manipulation of a few hundred manganese ions in a single gallium arsenide quantum well. Optically created mobile electron spins dynamically generate an energy splitting of the ion spins and enable magnetic moment orientation solely by changing either photon helicity or energy. These polarized manganese spins precess in a transverse field, enabling measurements of the spin lifetimes. As the magnetic ion concentration is reduced and the manganese spin lifetime increases, coherent optical control and readout of single manganese spins in gallium arsenide should be possible.
控制和监测单个自旋对于构建基于自旋的器件以及实现量子信息处理方案而言是很有必要的。与冷气体中的捕获离子一样，捕获在半导体晶格上的磁性离子具有均匀的特性和相对较长的自旋寿命。此外，半导体中的稀释磁矩可以与周围的主体强烈耦合，从而实现光学或电学的自旋操控。在此，我们描述了在单个砷化镓量子阱中对几百个锰离子进行的零场光学操控。通过光学手段产生的移动电子自旋动态地产生离子自旋的能量分裂，并仅通过改变光子螺旋度或能量就能实现磁矩取向。这些极化的锰自旋在横向场中进动，从而能够测量自旋寿命。随着磁性离子浓度的降低以及锰自旋寿命的增加，在砷化镓中对单个锰自旋进行相干光学控制和读出应该是可行的。
