Phonon Engineering the Coherence of Diamond Color Centers for Quantum NetworksONR White Paper Tracking Number 20-000000775
Abstract
This project will use high-frequency diamond quantum acoustics to improve the performance ofdiamond color centers for quantum networks. The scientific and engineering breakthroughsresulting from this research will help stabilize the spin-dependent optical transitions of diamondcolor centers, which are leading candidates for quantum network elements such as quantumrepeaters and quantum transducers. Active and passive quantum acoustic approaches to opticalline stabilization and optical coherence, as studied under this project, aim to improve the rate ofspin-photon entanglement. Entanglement between a long-lived spin qubit and a photon, and itsdistribution through quantum networks, is an important resource to enable distributed quantumcomputing and long-distance communication of quantum-secure messages.The research will focus on quantum acoustic interactions of diamond nitrogen-vacancy centers anddiamond silicon vacancy centers, each of which have a different profile of strengths and weaknessthat need to be addressed for quantum networking applications. The project will be organized intothree research thrusts. In thrust A, the research team will use microscale, semi-confocal bulkacoustic resonators to tune and stabilize nitrogen-vacancy center optical transitions. Byacoustically driving orbital resonance, the research team will examine orbital dynamicaldecoupling. The concept of dynamical decoupling has been extensively explored in the context ofquantum spin systems, and here the team will study these concepts applied to orbital states toenable more coherent optical transitions. In thrust B, the team will apply active acoustic drivingto the ground orbital states of diamond silicon-vacancy centers. Unlike nitrogen-vacancy centers,silicon vacancy centers have outstanding optical properties, but need improvement for theirassociated spin coherence. Because incoherent thermal processes limit silicon-vacancy center spincoherence, the team seeks to recover the coherence at more practical temperatures using twoapproaches. First, by coherently driving the orbital states at very high frequency, the team aims toaverage away the incoherent transitions that limit coherence. In the second approach, the teamwill engineer a phononic (vibrational) band gap to suppress incoherent thermal vibrations, thusproviding a passive mechanism to improve the spin coherence. In thrust C, the research team willengineer small-volume and ultra-high frequency diamond mechanical resonators at thefundamental limits of dissipation. Small volume resonators make the interactions between thecolor centers and the resonator stronger, providing both higher efficiency and a route to strongcoupling. High frequency resonators are a key ingredient to the active spin driving mentionedabove. Finally, the research team will seek to eliminate non-fundamental sources of mechanicaldissipation to enable diamond acoustic resonators with extremely high quality factors at lowtemperature.This proposed research will advance the state-of-the-art in diamond quantum acoustics and providethe scientific understanding and the techniques to improve the elements of a quantum network,relevant to defense priorities for quantum information technology
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 09, 2021
- Source ID
- N000142112614
Entities
People
- Gregory D Fuchs
Organizations
- Cornell University
- Office of Naval Research
- United States Navy