Skip to content

OSCAR-QUBE - student made diamond based quantum magnetic field sensor for space applications

MetadataDetails
Publication Date2022-04-01
Journal4th Symposium on Space Educational Activities
AuthorsBoo Carmans, Siemen Achten, Musa Aydogan, Sam Bammens, Yarne Beerden
InstitutionsIMEC, Hasselt University
Citations1
AnalysisFull AI Review Included

OSCAR-QUBE: Diamond Quantum Magnetometer for Space Applications

Section titled “OSCAR-QUBE: Diamond Quantum Magnetometer for Space Applications”

This document analyzes the OSCAR-QUBE project, focusing on the material science requirements for diamond-based quantum magnetometry, and outlines how 6CCVD’s advanced MPCVD capabilities can support the replication and advancement of this technology for space and terrestrial applications.


The OSCAR-QUBE project successfully demonstrated the viability of a diamond-based quantum magnetometer utilizing Nitrogen-Vacancy (NV) centers for magnetic field mapping in Low Earth Orbit (LEO) aboard the International Space Station (ISS).

  • Core Achievement: Development and deployment of a functional quantum sensor achieving a resolution of < 300 nT/sqrt(Hz) and a bandwidth of 1.3 kHz.
  • Material Requirement: The sensor relies on high-quality, radiation-hard diamond material containing NV centers, which are optically excited and addressed via microwave fields (ODMR).
  • Vector Sensing: The tetrahedral structure of the diamond lattice provides four crystallographic axes, enabling 3D vector magnetometry.
  • Technological Potential: The theoretical sensitivity of NV centers (down to 10 fT/sqrt(Hz)) highlights the potential for next-generation, high-precision quantum sensing in space and terrestrial fields (e.g., geology, navigation, biomedical imaging).
  • 6CCVD Value Proposition: 6CCVD provides the necessary high-purity, low-strain Single Crystal Diamond (SCD) substrates, along with custom metalization and polishing services, critical for optimizing NV center performance and integrating the sensor components.

The following hard data points were extracted from the research paper detailing the performance and physical constraints of the OSCAR-QUBE device.

ParameterValueUnitContext
Achieved Resolution< 300nT/sqrt(Hz)Measured in Low Earth Orbit (LEO)
Bandwidth1.3kHzSensor operational bandwidth
Device Size (Cube)10 x 10 x 10cm3Mechanical constraint of the OYT program
Device Weight420gTotal mass of the QUBE sensor
Power Consumption5WTotal power draw of the QUBE sensor
Theoretical Sensitivity (NV)Down to 10fT/sqrt(Hz)Potential theoretical limit [1]
Dynamic Range (NV)fT to 0.1TVery wide dynamic range capability [1]
Response Time (NV)< 200nsFast response capability [1]
NV Gyromagnetic Ratio (Îł)28.024GHz/TConstant used in ODMR calculation (Equation 1)

The OSCAR-QUBE sensor operates based on the principles of Optical Detection of Magnetic Resonance (ODMR) using NV centers in diamond.

  1. Material Foundation: The sensor utilizes the robust, radiation-hard properties of diamond, specifically leveraging the four crystallographic axes inherent in the tetrahedral lattice structure to enable 3D vector magnetometry.
  2. Optical Excitation: NV centers are initialized by excitation using green laser light, promoting the centers to an excited state.
  3. Spin-Dependent Relaxation: The centers relax back to the ground state via either a dark state or a fluorescent state (emitting red light), where the probability of relaxation is dependent on the spin state of the NV center.
  4. Microwave Addressing: A resonant microwave field is applied to address the spin state, resulting in a measurable dip in the red light intensity spectrum at the resonance frequency (the ODMR signal).
  5. Magnetic Field Detection: The presence of an external magnetic field causes Zeeman splitting, shifting the energy levels of the NV center. This shift is observed as a proportional change in the distance between the two resonance dips in the ODMR spectrum.
  6. Vector Field Calculation: By measuring the frequency difference (Δf) across the four crystallographic axes, the components of the magnetic field (Bx, By, Bz) are determined, allowing for the calculation of the 3D vector field.

6CCVD is uniquely positioned to supply the high-specification MPCVD diamond materials and custom fabrication services required for advanced quantum sensing projects like OSCAR-QUBE.

To achieve the high sensitivity and wide dynamic range demonstrated by NV centers, high-quality, low-strain diamond is essential.

Application Requirement6CCVD Material SolutionSpecification Match
High Coherence NV CentersOptical Grade Single Crystal Diamond (SCD)Provides the low defect density and high purity necessary to maximize NV center coherence time and achieve theoretical fT/sqrt(Hz) sensitivity.
Vector MagnetometryCustom-Oriented SCD SubstratesSCD plates grown with precise crystallographic orientation control, ensuring optimal alignment for addressing the four NV axes simultaneously.
Robust Space DeploymentSCD and Polycrystalline Diamond (PCD)Diamond’s inherent radiation hardness and thermal stability guarantee reliability in harsh space environments (LEO, ISS).
Large-Area Sensing ArraysInch-Size PCD Wafers (up to 125mm)For scaling up future sensor arrays or integrating multiple NV sensors onto a single, large platform.

The integration of the diamond sensor into the QUBE required precise engineering, particularly for optical access and microwave delivery. 6CCVD offers comprehensive customization services to meet these needs:

  • Custom Dimensions: 6CCVD provides SCD plates up to 500”m thick and PCD wafers up to 125mm in diameter, allowing for precise sizing of the diamond element to fit specific sensor geometries (e.g., the 10x10x10 cm3 cube constraint).
  • Advanced Polishing: Achieving high-fidelity optical coupling (green laser excitation, red light collection) requires exceptional surface quality. 6CCVD guarantees ultra-smooth polishing:
    • SCD: Surface roughness (Ra) < 1nm.
    • Inch-size PCD: Surface roughness (Ra) < 5nm.
  • Integrated Metalization: ODMR systems require microwave transmission lines (e.g., coplanar waveguides) deposited directly onto the diamond surface. 6CCVD offers in-house metalization capabilities, including: Au, Pt, Pd, Ti, W, and Cu. This streamlines the integration process for microwave components.

6CCVD’s in-house PhD team specializes in MPCVD growth parameters and material optimization for quantum applications. We can assist researchers replicating or extending the OSCAR-QUBE project by:

  • Material Selection: Consulting on the optimal nitrogen doping levels and post-growth processing (e.g., irradiation and annealing) required to maximize the density and quality of NV centers.
  • Design for Integration: Providing technical guidance on substrate thickness, orientation, and metalization schemes best suited for high-frequency microwave delivery and efficient optical collection in similar Quantum Magnetometry projects.
  • Global Logistics: Ensuring reliable, global shipping (DDU default, DDP available) of sensitive, high-value diamond components directly to research facilities worldwide.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Project OSCAR-QUBE (Optical Sensors Based on CARbon materials - QUantum BElgium) is a project from Hasselt University and research institute IMO-IMOMEC that brings together the fields of quantum physics and space exploration. To reach this goal, an interdisciplinary team of physics, electronics engineering and software engineering students created a quantum magnetometer based on nitrogen-vacancy (NV) centers in diamond in the framework of the Orbit-Your-Thesis! programme from ESA Education. In a single year, our team experienced the full lifecycle of a real space experiment from concept and design, to development and testing, to the launch and commissioning onboard the ISS. The resulting sensor is fully functional, with a resolution of < 300 nT/ sqrt(Hz), and has been gathering data in Low Earth Orbit for over six months at this point. From this data, maps of Earth’s magnetic field have been generated and show resemblance to onboard reference data. Currently, both the NV and reference sensor measure a different magnetic field than the one predicted by the International Geomagnetic Reference Field. The reason for this discrepancy is still under investigation. Besides the technological goal of developing a quantum sensor for space magnetometry with a high sensitivity and a wide dynamic range, and the scientific goal of characterizing the magnetic field of the Earth, OSCAR-QUBE also drives student growth. Several of our team members are now (aspiring) ESA Young Graduate Trainees or PhD students in quantum research, and all of us took part in the team competition of the International Astronautical Congress in October 2021, where we won the Hans Von Muldau award. Being an interdisciplinary team, we brought many different skills and viewpoints together, inspiring innovative ideas. However, this could only be done because of our efforts to keep up a good communication and team spirit. We believe that if motivated people work hard to improve the technology, we can change the way magnetometry is done in space.