Optical and electronic manipulation of spin coherence in semiconductors

Understanding how to manipulate and store information in the form of electronic and nuclear spin states may lead to exciting applications in quantum computing and spintronics. Electron spin polarization in semiconductors can be prepared optically and then manipulated using optical, electronic, and magnetic techniques. Optical studies of electron spin states reveal long coherence times in semiconductors, heterostructures, and quantum dots. Electron spin packets can be transported in a semiconductor and across heterojunctions with electric fields. Recent experiments demonstrate the possibility of performing quantum operations on electron spin states using femtosecond optical pulses or electrical gating. In addition, nuclear spin states can be controlled by their interactions with either periodically-excited electrons or ferromagnetic overlayers.