Quantum Sensor for D/H Ratio Measurement in Water in Outer Planets

The study of the ratio of deuterium to hydrogen (D/H) isotopes allows the determination of whether the water originated from comets and asteroids, or it was formed through processes such as solar wind implantation or outgassing from a moons interior. This information can provide insight into the early history and formation of the moon and the inner Solar System, with significant implications for future lunar exploration and the development of sustainable space exploration programs.We have designed an innovative quantum sensor for D/H ratio measurement in water using spin centers as a probe for detecting nuclear spins of the isotopes. The proposed sensor indirectly measures the D/H ratio by interrogating shallow spin centers included within the walls of a container using optical and a combination of radio frequency (RF) and microwave (MW) signals. By confining the sample in a small container volume, this proposed sensor limits the effects of diffusion noise and enhances the samples polarization without requiring hard to implement techniques such as hyperpolarization, thus providing higher resolution capability using simpler setups. Due to their low-cost and improved size, weight and power consumption, the proposed sensors could cover the growing need for robust sensors with small footprints suitable forin-situmeasurements in space missions. The principal Phase II deliverable will be a compact, robust, room-temperature quantum NV-NMR sensor optimized for application to address measurements of D/H ratio in water. This device involves a bottom illumination/detection configuration, adding a microfluidic transparent chamber for optical readout and a coplanar waveguide (CPW) to deliver MW multi-pulse sequences. We will characterize device performance, including magnetic-field sensitivity, noise, and power consumption to confirm the devices effectiveness for NASA requirements and aligning with device simulations. We designed a quantum sensor for D/H ratio measurement in water using spin centers (spin states originated from point defects in the crystal lattice) as a probe for detecting nuclear spins of the isotopes. The proposed sensor indirectly measures the D/H ratio by interrogating shallow spin centers included within the walls of a container using optical and a combination of radio frequency (RF) and microwave (MW) signals. By confining the sample in a small container volume, our sensor limits the effects of diffusion noise and enhance the sample’s polarization without requiring hard to implement techniques such as hyperpolarization thus providing higher resolution capability using simpler setups. We calculated a sensitivity improvement of up to 5 orders compared to classical NMR systems. Due to their low-cost and improved size, weight and power consumption, the proposed sensors could cover the growing need for robust sensors with small footprints suitable for in-situ measurements in space missions. The technical objectives focus on delivering a cost-effective quantum sensor NV NMR device. We have developed a mitigation plan to address any issues related to its fabrication and characterization for D/H ratio measurement in water. A main objective is to continue the development of our Phase I CAD kit for device performance such as sensor sensitivity and nuclear spin densities of the isotopes of interest. A second objective is to engineer a bottom illumination/detection configuration, adding a microfluidic transparent chamber for optical readout and a coplanar waveguide (CPW) to deliver MW multi-pulses sequences. We will modify and optimize a high-tech and cost-effective NV optical magnetometry setup for this purpose, optimizing the different optical components. A third objective is to characterize device performance, including magnetic-field sensitivity, noise, and power consumption. This evaluation will confirm the device’s effectiveness for NASA requirements and aligning with device simulations. In addition to descriptive reports the principal Phase II deliverable will be a compact, robust, room-temperature NMR sensor optimized for application to address measurements of D/H ratio in water. We estimate a sensitivity improvement of up to 5 orders of magnitude compared to classical NMR systems, leveraging the high achievable density n of sensing spins.
Benefits: We have demonstrated in this project a novel sensor for measuring D/H ration in water. The competitive advantage of our sensor is that it will simplify the device by integrating the sensor and electronic components into a single chip, leading to improved predictability and sensitivity unparallel to classical NMR systems. They are exceptionally small and would thus be very well suited for nanosats or picosats as their size, power, and complexity restrictions are most severe. The development of nano-NMR quantum sensors based on diamond or SiC will likely lead to an array of additional sensing and information processing technologies such as radiation hardened sensors as well as potentially quantum memories for quantum communication and various components for quantum computation. The spin defects are also sensitive to electric fields, temperature, and other fields.