Quantum Information Processing and Metrology Using Few Electron Spins in Solids
Many different physical realizations of quantum bits have been studied over the past decade, including trapped ions, nuclear spins of molecules in solution, Josephson junctions and more. Among the different possible realizations, solid-state implementations have attracted considerable interest due to their promise in miniaturization and scaling, taking advantage of existing technology for fabrication. The spin qubit is one such example where a quantum bit of information is encoded in the spin state of a single electron confined to a small spatial dimension. In this talk I will discuss some of our recent work on single electron spin qubits in GaAs quantum dots and color centers in diamond. In these systems spin decoherence arises predominantly from the interaction with proximal paramagnetic spins such as nuclear spins of the host lattice. However, the slow dynamics of this environment lends itself to effective decoupling schemes that allow extending coherence to nearly a millisecond. Paradoxically, coupling to the seemingly random environment of nuclear spins provides valuable resources for storage, single shot readout and fast manipulation of quantum information with important applications to quantum information processing and metrology.