Quantum spin-mechanics: A new solid-state platform for quantum computing - Hailin Wang

Mechanical degrees of freedom, often ignored or overlooked by quantum physicists, play a pivotal role in trapped ions, thus far the most successful experimental platform for quantum computing. Central to the remarkable success of the trapped ion system is the control of the collective mechanical motion at the level of a single phonon. Extending the ideas and concepts underlying the trapped-ion quantum computing paradigm to a macroscopic or mesoscopic spin-mechanical system, in which an electron spin couples strongly to a nanomechanical oscillator, opens up a new frontier for exploring quantum physics in a macroscopic system and establishes a new solid-state platform for quantum computing. In this talk, I will discuss our recent experimental advance in developing a diamond-based spin-mechanical system. We have successfully realized a solid-state analog of trapped ions by using ground electron spin states of nitrogen vacancy (NV) centers in diamond as robust spin qubits and also by taking advantage of the strong excited-state strain coupling of NV centers for spin-mechanical coupling. We exploit adiabatic evolution of the ground spin states such that the spin qubits are subject to the excited-state strain coupling through optical interactions, but are nearly immune to decoherence of the excited state.