The objective of this EAGER proposal is to determine the feasibility of a scalable quantum optical network based on NV-centers in diamond coupled to gallium phosphide (GaP) photonic devices. Two critical components necessary for scalability will be fabricated and implemented: (1) large-area GaP-diamond integration and device fabrication and (2) independent electrical tuning of quantum device frequencies on the same chip. If successful, this research will pave the way toward a large-scale quantum information processor (QIP) that could be utilized for secure communication, quantum algorithms, and quantum simulation.
Intellectual Merit: This research proposal identifies the GaP-diamond hybrid material system as an extremely promising system to realize a scalable measurement-based quantum information network. In the hybrid system, the GaP provides the photonic device layer while the diamond nitrogen-vacancy (NV) center provides the photon-coupled spin qubit. The proposed work addresses the major challenges in diamond-GaP integration. The first specific goal of this project is the deterministic transfer and bonding of a GaP membrane to a diamond chip with an area capable of supporting one hundred integrated devices. In addition to QIP applications, the technique developed is expected to have applications in classical photonics due to GaP's wide bandgap and electro-optic properties. The second goal is the electric tuning of near-surface NV centers onto resonance with on-chip GaP cavities in three or more devices on the same chip. If realized, this will be the first demonstration of device specific electrical tuning of a quantum emitter onto an optical cavity resonance and will be an important milestone for all photonic-spin solid-state qubit systems.
Broader Impacts: The development of NV centers integrated into on-chip optical devices is expected to lead to scalable quantum information processing (QIP). Scalable QIP will enable long-distance secure communication, factoring of products of large-prime numbers in polynomial time, and the efficient simulation of many-body quantum systems critical for engineering new materials. Historically, scalability has proven to be a challenge in quantum information processing because typically quantum bits with good quantum properties have not been realized in a solid-state system, prohibiting device fabrication and integration. Broader impacts of the proposed research process include developing public software to implement finite-difference-time-domain (FDTD) electromagnetic simulations on a virtual computer cluster on the Amazon cloud and training both graduate and undergraduate students.