Diamond, known for its paramount significance in quantum sensing, faces restrictions due to its size, thereby limiting its applications. Recent investigations emphasize the potential of hBN to succeed diamond, particularly after methods were developed by TMOS researchers to stabilize hBN’s atomic imperfections and examine its different charge states, paving the way for its use in devices where diamond is unsuitable.
For ages, diamond has dominated the quantum sensing field, due to its nitrogen-vacancy centers with coherent control, adjustable spin, sensitivity to magnetic fields, and the ability to work at ambient temperatures. With a material so aptly fitting and simple to fabricate on a large scale, the pursuit of substitutes for diamond has not been a priority.
Yet, this giant of the quantum world has a shortcoming. Its sheer size becomes a barrier. Analogous to an NFL linebacker not being the ideal choice as a jockey in the Kentucky Derby, diamond fails to meet the demands of quantum sensors and data handling. The highly stable defect, a well-known quality of diamonds, starts to degrade when the diamond’s size is reduced, rendering it ineffectual beyond a certain point.
Introducing hBN.
Previously ignored as a quantum sensor and a medium for quantum information processing, hBN gained attention when new defects were detected that could challenge Diamond’s nitrogen-vacancy centers. Among these, the boron vacancy center (a solitary missing atom in the hBN crystal structure) appears to be the most promising thus far.
At TMOS, experimental arrangements were made to study the boron vacancy defects in hBN. Credit: TMOS, the ARC Centre of Excellence for Transformative Meta-Optical Systems
The various charge states of the boron vacancy are an essential aspect, with only the -1 charge state being suitable for spin-oriented applications. Detecting and examining the other charge states has been difficult, creating issues as the charge state can oscillate between the -1 and 0 states, causing instability, particularly in environments typical for quantum gadgets and sensors.
As delineated in a paper published in Nano Letters, TMOS researchers have formulated a method to stabilize the -1 state, and an innovative experimental technique to study the charge states of defects in hBN, applying optical stimulation and concurrent electron beam exposure.
Angus Gale and Dominic Scognamiglio, the lead authors, in their research laboratory. Credit: TMOS, ARC Centre of Excellence for Transformative Meta-Optical Systems
Angus Gale comments, “This research illustrates that hBN can potentially supersede diamond as the favored substance for quantum sensing and quantum information processing since we can stabilize the atomic flaws that are fundamental to these applications, resulting in 2D hBN layers that could be assimilated into devices where diamond can’t.”
Dominic Scognamiglio adds, “The properties of this material are unique and intriguing, but the study of hBN is in its infancy. The literature lacks publications on charge state transitioning, manipulation, or stability of boron vacancies, hence we are pioneering this field and enhancing our comprehension of this material.”
Milos Toth, Chief Investigator, projects, “The ensuing phase of this research will concentrate on pump-probe measurements to fine-tune defects in hBN for uses in sensing and integrated quantum photonics.”
Quantum sensing is evolving swiftly. Quantum sensors offer superior sensitivity and spatial precision compared to traditional sensors. One of its vital applications includes precise nanoscale sensing of temperature, electric, and magnetic fields in microelectronic devices – a key element in Industry 4.0 and advancing the miniaturization of gadgets. Accurate quantum sensing will mitigate overheating of microchips and amplify performance and dependability.
Furthermore, quantum sensing bears significant potential in the medical technology domain, where it may serve as an injectable diagnostic agent to locate cancer cells or monitor cellular metabolic activities to evaluate the effects of medical treatments.
To investigate boron vacancy defects in hBN, the TMOS team designed an innovative experimental system that amalgamated a confocal photoluminescent microscope with a scanning electron microscope (SEM), permitting them to manipulate the charge states of boron vacancy defects while measuring the flaw.
Gale observes, “The methodology is groundbreaking as it enables us to direct the laser to individual defects in hBN, while manipulation is performed using electronic circuits and an electron beam. This adjustment to the microscope is unparalleled; it was extraordinarily beneficial and enhanced our workflow remarkably.”
Reference: “Manipulating the Charge State of Spin Defects in Hexagonal Boron Nitride” by Angus Gale, Dominic Scognamiglio, Ivan Zhigulin, Benjamin Whitefield, Mehran Kianinia, Igor Aharonovich, and Milos Toth, 26 June 2023, Nano Letters.
DOI: 10.1021/acs.nanolett.3c01678
The research was financially supported by the Australian Research Council.
Table of Contents
Frequently Asked Questions (FAQs) about hBN
What has been the traditional role of diamond in quantum sensing?
Diamond has held a prominent position in quantum sensing due to its nitrogen-vacancy centers, adjustable spin, and magnetic field sensitivity. Its capacity to operate at room temperature has also been a significant advantage.
How does hBN compare to diamond in quantum sensing applications?
Recent research highlights hBN’s potential as a replacement for diamond in quantum sensing applications. Unlike diamond, hBN can address the limitations posed by size constraints, expanding its potential use cases.
What is the significance of stabilizing atomic defects in hBN?
Researchers at TMOS have successfully developed methods to stabilize atomic defects in hBN. This breakthrough opens doors for integrating hBN into devices where diamond’s size becomes a limiting factor, thereby enhancing the versatility of quantum technologies.
What is the boron vacancy center in hBN?
The boron vacancy center is a specific defect in the hexagonal boron nitride (hBN) crystal lattice. This defect has emerged as a promising candidate for applications in quantum sensing and quantum information processing.
How do the charge states of boron vacancy defects impact their use in quantum applications?
The boron vacancy defect can exist in various charge states. Among these, the -1 charge state is suitable for spin-based applications. However, the instability of other charge states has been a challenge, especially in typical quantum device environments.
How did researchers address the challenges posed by charge state instability in hBN defects?
Researchers from TMOS developed a method to stabilize the -1 charge state of boron vacancy defects. They also introduced an innovative approach involving optical excitation and concurrent electron beam irradiation to study and manipulate these defects.
What potential applications can hBN have beyond quantum sensing?
Apart from quantum sensing, hBN’s unique properties hold promise in various fields, including integrated quantum photonics, nanoscale temperature sensing, and applications in the medical technology sector, such as cancer cell detection and monitoring metabolic processes.
What is the significance of integrating confocal photoluminescent microscopy with a scanning electron microscope?
The integration of these two advanced microscopy techniques allowed researchers to simultaneously manipulate the charge states of boron vacancy defects while observing and measuring these defects. This novel approach streamlined their workflow and enhanced their understanding of hBN’s properties.
How does this research contribute to the advancement of quantum technologies?
The research conducted by TMOS researchers contributes to the ongoing development of quantum technologies by expanding the materials palette for quantum sensing and quantum information processing. It addresses key challenges related to stability and manipulation of defects, paving the way for practical applications.
What are the future directions of this research?
The next phase of this research will focus on pump-probe measurements to optimize defects in hBN for sensing and integrated quantum photonics applications. This research is poised to shape the future landscape of quantum technology and its practical applications.
More about hBN
- Diamond’s Downfall: The Quantum World’s Next Top Material
- TMOS – ARC Centre of Excellence for Transformative Meta-Optical Systems
- Paper: “Manipulating the Charge State of Spin Defects in Hexagonal Boron Nitride”
- Australian Research Council
3 comments
diamond rocked d quantm world but got size issue. hBN enter scene, surprisinly good! TMOS heroes, fixin defects, bring new era. Excitin read!
quantum sensin is big, diamond wuz kewl, hBN sounds promisin tho. TMOS doin thier thing, stablizin stuff. gotta check that paper too.
diamond’s quantum reign challenged! hBN sounds fancy, TMOS peeps playin hero. defects? stablized! future’s bright, hBN in quantum cars maybe?