Scientists have made a breakthrough in the control of single electrons in solid matter, by decoupling a single quantum mechanical spin from its environment for the first time. This opens new possibilities for using impurity atoms as highly sensitive nanoscale magnetic sensors, and potentially, as qubits (quantum binary digits) for larger-scale quantum information processing. Nitrogen-vacancy centers in diamond have attracted attention due to the potential uses of their unusual magnetic and optical properties, but their fragile quantum states are easily destroyed by miniscule interactions with the outside world. The research team achieved reliable control over the single quantum magnetic moments (spins) of nitrogen-vacancy centers by applying a specially designed sequence of high-precision electromagnetic pulses, and they were able to protect the quantum state of a single spin and make it evolve as if it were completely decoupled from the external world. This increased the lifetime of the quantum spin state 25-fold at room temperature.
- G. de Lange, Z. H. Wang, D. Ristè, V. V. Dobrovitski, and R. Hanson "Universal Dynamical Decoupling of a Single Solid-State Spin from a Spin Bath" Science Express Reports, 2010, 1126, 1192739