Jörg Wrachtrup, Universität Stuttgart
Abstract
Condensed matter physicists strive for engineering quantum states with a precision formally only reached in atom or quantum optics. However, usually the many degrees of freedom in solids hamper any fine control. Since a few years a number of attempts have been successful to fabricate solid state systems which allow high precision control of quantum states as well as the engineering of complex quantum states. Among those systems are defects in diamond. By implantation of atomic impurities single defect centers can be created with high spatial accuracy. Those defects show quasi atomic states which can be electron paramagnetic, being effectively shielded by the diamond lattice from environmental disturbances. Precise implantation allows mutual coupling of defects and the generation of two or multiple particle state. Quantum non-demolition and feedback algorithms give full access to enhanced quantum state preparation and measurement methodology. Since diamond defects can be operated in the quantum regime at ambient conditions all those methods can be applied to sensing applications. As an example diamond defects are very sensitive detectors for external magnetic fields. Eventually this is of use for e.g. measuring small magnetic fields of single electron or even proton spins in complex environments in e.g. biological media.