Abstract

Solid state spin qubits are promising candidates for quantum information processing due to their long coherence time, and high tolerance on environments. However, their good isolation from the environment also poses challenges for achieving controlled interactions and entanglement in multi-solid-state-qubit systems. In this talk, I will discuss our efforts of leveraging the dynamics of mechanical resonators to mediate the coupling between distant spins. More specifically, we demonstrated the coupling between a single nitrogen-vacancy (NV) center in a diamond nanopillar and a magnetically functionalized silicon nitride nanobeam mechanical resonator via the magnetic field gradients. We showed the feasibility of coherent manipulation of a spin qubit in the proximity of a transported micromagnet by utilizing the nearby nuclear spin as a local quantum memory. By analyzing the requirements for high-fidelity, phonon-mediated gate operations at a level of control that is competitive with other platforms, such an approach holds promise for scaling up to realize potential programmable solid-state-qubit-based quantum processors. Furthermore, I will briefly outline the prospect of utilizing the solid state spin qubit to manipulate states of macroscopic mechanical resonators, even potentially preparing them in exotic quantum states.
 

Biosketch

Yiqi is a Harvard Quantum Initiative postdoctoral fellow at Harvard physics department and Harvard Quantum Initiative, supervised by Prof. Mikhail Lukin. His current work aims to explore the interface between spin qubits (NVs) and mechanical degrees of freedom for potential quantum applications. His research interests include exploring applications of hybrid quantum systems and testing quantum theories in macroscopic scales.  Prior to that, Yiqi received his Ph.D. (2023) from Yale, where he has worked on experimental quantum optomechanics.

Please contact phweb@ust.hk should you have questions about the talk.