Dynamical Decoupling In Solids

To exploit the quantum coherence of electron spins in solids in future tech-nologies such as quantum computing, it is first vital to overcome the problem of spin decoherence due to their coupling to the noisy environment. Dynami-cal decoupling, which uses stroboscopic spin flips to give an average coupling to the environment that is effectively zero, is a particularly promising strategy for combating decoherence because it can be naturally integrated with other desired functionalities, such as quantum gates.In this thesis we experimentally investigate the performance of dynamical de-coupling method in suppressing decoherence, especially in spin-based solids. First, we use pulsed electron paramagnetic resonance to demonstrate Uhrig dynamical decoupling for preserving electron spin coherence in irradiated malonic acid crys-tals at temperatures from50K to room temperature. By comparing experiments with microscopic theories, we have identified the relevant electron spin decoher-ence mechanisms in solids. Then we turn to a two-qubit system, the phosphorous doped in silicon which is consisted of one electron spin and one nuclear spin, to study dynamical decoupling in protecting two-qubit entangled state. After that we further apply dynamical decoupling method to enhance the precision of phase metrology in a multi-round phase estimation experiment realized in single elec-tron spin in NV center. Finally, we show a robust two-qubit gate by integrating with dynamical decoupling and discuss other strategies to realize robust arbitrary quantum control without exploring dynamical decoupling method.