Long-lived solid-state room-temperature quantum memory

One of the major obstacles in quantum information technology is to prevent a quantum bit (qubit) from dephasing, while still being able to manipulate and readout the qubit state on a fast time scale. We report recent progress towards the realization of a room temperature quantum register that maintains it's quantum mechanical nature for seconds while still allowing for qubit manipulation in the MHz regime. To achieve this, we utilize a quantum register consisting of an electronic ancilla spin and a proximal nuclear memory spin; the register is associated with single nitrogen-vacancy (NV) defect centers in diamond. In order to maximize the coherence time of the nuclear spin, we employ dynamical decoupling using microwave and optical pulses. The realization of a solid state quantum memory with long coherence times at room temperature opens up new possibilities for applications of quantum information systems.