Editorial Feature

The Use of Diamonds in Quantum Computers

Optically active defects in diamonds make them promising candidates for qubits, which are the building blocks of quantum computers. Diamonds are ideal materials for constructing devices that harness the quantum mechanical properties of coherence and entanglement. This article explores the potential of diamonds in quantum computing and addresses the associated challenges.

Diamonds in Quantum Computers, quantum diamonds

Image Credit: Ievgeniiya Ocheretna/Shutterstock.com

What are Quantum Computers?

Quantum computers employ quantum physics to process and store data, thus enabling them to solve problems that are unsolvable by conventional computers. These computers aid in the understanding, modeling, and manipulation of other quantum systems.

Consequently, physicists can design devices that operate at scales where quantum mechanics becomes crucial, such as computer chips, energy technologies, communication devices, scientific instruments, clocks, sensors, and materials.

Similar to conventional computers, quantum computers have chips, circuits, and logic gates, and their operations are guided by algorithms that use binary codes of ones and zeros to represent information. However, quantum computers employ qubits (quantum bits) to process information differently.

While classical bits always represent either one or zero, a qubit can exist in a state of superposition, where it is simultaneously in a state of one and zero until it is measured. Furthermore, the states of multiple qubits can become entangled, implying that they are mechanically linked to one another. Superposition and entanglement provide quantum computer abilities that are unavailable in classical computing.

N-V Centers in Diamonds

Diamonds are electrical and high thermal conductors. They possess a nitrogen-vacancy (N-V) impurity, where nitrogen substitutes for carbon while its neighboring position is vacant. Unlike other potential quantum computing systems, N-V impurities in diamonds can be created and manipulated at room temperature. 

A single electron (unpaired electron) circulating in the N-V center can be excited or polarized by the laser. When the unpaired electron is excited, de-excitation to a lower energy state results in the emission of a single photon. 

The ability of a single electron to exist in a quantum superposition, where it possesses both spin-up and spin-down states, renders it a promising candidate for use as a qubit. As the foundation of a quantum computer, a qubit represents one that can exist in multiple states simultaneously, such as zero and one.

The manipulation of N-V impurities has been reported by two researchers, Ronald Hanson and Mikhail Lukin. Ronald Hanson from the University of California, Santa Barbara, achieved electron spin resonance, where they flipped the single electron's spin in an N-V center, which lost its polarization on interacting with nearby nitrogen impurities. These interactions are regulated by adjusting the external magnetic field.

Similarly, Mikhail Lukin of Harvard University was able to detect the spin of a single carbon-13 nucleus in a diamond by its effect on the electron spins in nearby N-V centers. Accordingly, Lukin can detect weak magnetic fields in the carbon-13 (13C) atoms. This method can be used for precise magnetic resonance imaging.

N-V Centers for Quantum Computing and Quantum Networks

 N-V centers in diamonds have emerged as a leading option for realizing quantum technologies. They behave like individual atoms within a solid structure featuring long-lived spin quantum states and clear optical transitions. These centers possess spin properties derived from both their bound electrons and surrounding nuclear spins, similar to those of atoms.

Optical transitions can be used to manipulate these spins, and the solid diamond foundation facilitates rapid electrical and magnetic control through on-chip wiring and waveguides. Engineers can design photonic structures from diamond crystals to form dependable optical connections. In recent years, research laboratories worldwide have leveraged atom-like characteristics and solid-state control to demonstrate various critical functions that are essential for quantum technologies.

Recent Studies

An article published in Philosophical Transactions of the Royal Society A examined the isotopic shift of neutrally charged silicon-vacancy defect (SiV0) centers in chemical vapor deposition (CVD)-grown epitaxial layers of isotopically enriched 12C and 13C diamonds, as well as in diamond with natural isotope composition but doped with only one isotope of Silicon (28Si, 29Si, and 30Si).

The shift in energy detected was 1.60 meV for the 12C/13C couple and 0.33 meV for the 28Si/29Si and 29Si/30Si couples, which were close to isotopic shift values obtained previously for the negatively charged silicon vacancy (SiV-), indicating a comparable model of interaction with the environment for these two charge states of the SiV color centers.

One of the significant findings of this study was that for quantum applications of SiV0 centers, it is essential to use isotopically pure carbon rather than isotopically pure silicon to achieve a narrower spectral line.

Nitrogen-vacancy centers are typically created from single substitutional nitrogen centers, referred to as P1 centers in diamond. P1 centers are produced through a process of irradiation followed by annealing at temperatures of 700°C or higher.

Insight into the spatial distribution of P1 centers is essential for diamond-based sensors and quantum devices. P1 centers play a crucial role in dynamic nuclear polarization (DNP) quantum sensing, as they serve as polarization sources and affect the relaxation of N-V centers.

A study published in the Journal of the American Chemical Society employed DNP and pulsed electron paramagnetic resonance (EPR) techniques, which revealed a clustered population of P1 centers that exhibited exchange coupling and produced asymmetric line shapes.

 The 13C DNP profile at a high magnetic field displayed a pattern that required an asymmetric EPR line shape for the P1 clusters, which had electron-electron (e-e) coupling strengths greater than the 13C nuclear Larmor frequency.

To determine the energy contributions from various e-e couplings, EPR and DNP characterization at high magnetic fields was necessary.  The observation of clustered P1 centers and the associated asymmetric line shapes offered a new and essential understanding of magnetic noise sources for the quantum information applications of diamonds.

The research team suggested that room-temperature 13C DNP in a high field, which can be achieved through simple modifications of existing solution-state nuclear magnetic resonance (NMR) systems, is a powerful tool for evaluating and controlling diamond defects.

Conclusion

To summarize, diamonds are promising candidates for qubits, the fundamental components of quantum computing, due to their optically active defects. The N-V centers, in particular, make them suitable for exploiting the quantum properties of coherence and entanglement, which are essential for quantum computers. Although there are obstacles to their practical application, ongoing research continues to investigate their potential and address the associated difficulties.

More from AZoQuantum: Leveraging Quantum Discord in Supervised Learning Through DQC1

References and Further Reading 

Boldyrev, K. N., Sektarov, E. S., Bolshakov, A. P., Ralchenko, V. G., Sedov, V. S. (2024). SiV0 centers in diamond: effect of isotopic substitution in carbon and silicon. Philosophical Transactions of the Royal Society A, 382(2265), 20230170. https://doi.org/10.1098/rsta.2023.0170

Bussandri, S., Shimon, D., Equbal, A., Ren, Y., Takahashi, S., Ramanathan, C., Han, S. (2023). P1 Center Electron Spin Clusters Are Prevalent in Type Ib Diamonds. Journal of the American Chemical Society. https://doi.org/10.1021/jacs.3c06705

What Is Quantum Computing? Accessed on 24 December 2023

Diamond Sparkles in Quantum Computing Accessed on 24 December 202

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Bhavna Kaveti

Written by

Bhavna Kaveti

Bhavna Kaveti is a science writer based in Hyderabad, India. She has a Masters in Pharmaceutical Chemistry from Vellore Institute of Technology, India, and a Ph.D. in Organic and Medicinal Chemistry from Universidad de Guanajuato, Mexico. Her research work involved designing and synthesizing heterocycle-based bioactive molecules, where she had exposure to both multistep and multicomponent synthesis. During her doctoral studies, she worked on synthesizing various linked and fused heterocycle-based peptidomimetic molecules that are anticipated to have a bioactive potential for further functionalization. While working on her thesis and research papers, she explored her passion for scientific writing and communications.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Kaveti, Bhavna. (2024, January 10). The Use of Diamonds in Quantum Computers. AZoQuantum. Retrieved on July 17, 2024 from https://www.azoquantum.com/Article.aspx?ArticleID=485.

  • MLA

    Kaveti, Bhavna. "The Use of Diamonds in Quantum Computers". AZoQuantum. 17 July 2024. <https://www.azoquantum.com/Article.aspx?ArticleID=485>.

  • Chicago

    Kaveti, Bhavna. "The Use of Diamonds in Quantum Computers". AZoQuantum. https://www.azoquantum.com/Article.aspx?ArticleID=485. (accessed July 17, 2024).

  • Harvard

    Kaveti, Bhavna. 2024. The Use of Diamonds in Quantum Computers. AZoQuantum, viewed 17 July 2024, https://www.azoquantum.com/Article.aspx?ArticleID=485.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Your comment type
Submit

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.