OPTIMIZING QUBIT PERFORMANCE IN DIAMOND WITH STRAIN ENGINEERING
Abstract
Spin qubits in diamond are a leading material platform in quantum sensing and quantum communication. Recently, group-IV color centers in diamond have risen to prominence in quantum photonics due to their excellent optical coherence. However, coherent operation of group-IVs necessitates operation in dilution refrigerators at sub-Kelvin temperatures with vector magnets. These systems are costly ($600K) and resource intensive, requiring entire rooms for operation. This significantly impedes efforts to scale networking technologies in diamond. Here, we develop strain engineering in diamond to optimize performance of group IV color centers. We are generating tunable diamond membranes that host coherent color centers. We have found simple methods to generate large, static strain profiles in the membranes. This strain, on the order of 0.1-0.5% dramatically modifies the electronic structure of group-IVs. With these modifications, the spin coherence of group IV color centers can significantly exceed 10 ms at T = 4 K, sufficient for long-range quantum networking applications. Additionally, the modified electronic structure enables efficient microwave control of the qubit spin and eliminates the need for vector magnets. With strain-enhanced group-IV qubits, the cost and infrastructure required for network nodes reduces by ten-fold, to $50K for a 4 K closed-cycle cryostat. This can significantly ease the scaling of quantum networks. We will test these strain-enhanced qubits in a comprehensive three-year research program. We will experimentally study the interplay of strain engineering and critical quantum state properties - specifically spin- and optical-coherence, optical cycling, microwave control - and their sensitivity to magnetic field alignment. We have built a full theoretical model of the electron structure of group IV color centers under strain. Additionally, we will determine the limits of substrate- and patterning-induced strain, and explore methods to integrate fine-tuned strain control.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 20, 2023
- Source ID
- FA95502210518
Entities
People
- Alexander A. High
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Chicago