Controlling Single Electron Spins in Solids


Theoretical analysis and simulations provided control strategies to extend the coherent quantum states of single electron spins 25-fold at room temperature.  The related experiments demonstrate the ability to dynamically decouple a single quantum mechanical spin from its environment for the first time, which opens new possibilities for highly sensitive magnetic sensors, and possibly for qubits for larger scale quantum information processing. Nitrogen-vacancy centers in diamond have unusual magnetic and optical properties with potential uses, 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. 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.