Researchers from the University of Chicago, California Institute of Technology, and Stanford University have proposed a new solution for long-distance quantum communication. The Vacuum Beam Guide (VBG) uses an array of lenses in a vacuum to guide light, overcoming limitations of existing fibre and satellite technologies. The VBG can outperform the best fibre by three orders of magnitude in terms of attenuation rate, enabling long-range quantum communication over thousands of kilometres. This could revolutionise quantum networks, enabling applications such as global-scale secure quantum communication and delegated quantum computing.
By addressing the challenge of lossy quantum channels, our high-throughput VBG has the potential to revolutionize quantum networks, enabling a wide range of exciting novel quantum network applications, such as global-scale secure quantum communication, ultra-long-based optical telescopes, quantum network of clocks, quantum data centers, and delegated quantum computing
Yuexun Huang, Francisco Salces – Carcoba, Rana X Adhikari, Amir H. Safavi-Naeini, and Liang Jiang
Introduction to Vacuum Beam Guide (VBG) for Quantum Networks
A team of researchers from the Pritzker School of Molecular Engineering at the University of Chicago, the Division of Physics, Math, and Astronomy at the LIGO Laboratory, California Institute of Technology, and the Department of Applied Physics and Ginzton Laboratory at Stanford University have proposed a novel solution for quantum channels. The solution, known as the Vacuum Beam Guide (VBG), aims to overcome the limitations of existing fiber and satellite technologies for long-distance quantum communication. The article is titled: “Vacuum Beam Guide for Large Scale Quantum Networks” and published in arxiv.
The VBG Solution
The VBG uses an array of aligned lenses spaced kilometers apart, offering ultra-high transparency over a wide range of optical wavelengths. With realistic parameters, the VBG can outperform the best fiber by three orders of magnitude in terms of attenuation rate. This means that the VBG can enable long-range quantum communication over thousands of kilometers with a quantum channel capacity beyond 1013 qubit/sec, which is significantly higher than the current quantum satellite communication rate.
The Challenge of Building an Effective Low-Loss Quantum Channel
Building an effective low-loss quantum channel for global-scale quantum networks is a significant challenge. The main obstacle is the absorption loss of optical channels, with attenuation length limited to tens of kilometers for fiber and free-space channels. This results in a significant decrease in the direct quantum communication rate over long distances. While progress has been made in extending the communication distances for quantum networks, including satellite-based quantum entanglement distribution over 1200 km and memory-enhanced quantum communication, these solutions are still limited.
The VBG Approach
The VBG approach uses an array of lenses in an evacuated tube to guide light, as opposed to relying on total reflection induced by fiber. The large vacuum spacing between lenses significantly reduces the effective travel length of light in optical materials, thus eliminating the problem of material absorption. The VBG channel is set up within a vacuum chamber tube, which eliminates air absorption and effectively isolates the channel from the outer environment, ensuring robustness against environmental perturbations.
The Potential of VBG
The design of the vacuum beam guide has the potential to achieve ultra-low-loss long-distance communication. With the ability to build large-scale vacuum chambers hosting precision optical elements separated by multiple kilometers, we can make exciting scientific discoveries, such as gravitational wave detection by the Laser Interferometer Gravitational-wave Observatory (LIGO).
The VBG as the Backbone Quantum Channel
The researchers propose deploying the VBG as the backbone quantum channel toward a global quantum network with a hierarchy structure. Their estimation demonstrates the VBG as state-of-the-art under a practical and exemplifying configuration, establishing it as one of the most practical and potentially useful quantum communication techniques at a global scale.
Summary and Outlook
The VBG scheme enables the implementation of a highly transparent and reliable optical quantum channel with an effective attenuation length of over 104 km and a large communication bandwidth. With currently available technology, the VBG can establish a continuous quantum channel connecting remote quantum devices with an ultra-high quantum capacity above 1013 qubits/second over continental scales. By addressing the challenge of lossy quantum channels, the high-throughput VBG has the potential to revolutionize quantum networks, enabling a wide range of exciting novel quantum network applications.
With an array of aligned lenses spaced kilometers apart, the VBG offers ultra-high transparency over a wide range of optical wavelengths. With realistic parameters, the VBG can outperform the best fiber by three orders of magnitude in terms of attenuation rate.
With currently available technology, the VBG can establish a continuous quantum channel connecting remote quantum devices with an ultra-high quantum capacity above 1013 qubits/second over continental scales, orders of magnitude higher than other approaches using satellites and quantum repeaters.
The Vacuum Beam Guide (VBG) offers a new solution for long-distance quantum communication, outperforming existing fibre and satellite technologies by using an array of aligned lenses spaced kilometres apart, providing ultra-high transparency over a wide range of optical wavelengths. This ground-based, low-loss, high-bandwidth quantum channel could enable long-range quantum communication over thousands of kilometres, with a quantum channel capacity significantly higher than current quantum satellite communication rates, potentially revolutionising quantum networks and applications such as secure quantum communication and delegated quantum computing.
- Researchers from the University of Chicago, California Institute of Technology, and Stanford University have proposed a new solution for long-distance quantum communication, called the Vacuum Beam Guide (VBG).
- The VBG uses an array of aligned lenses spaced kilometres apart, offering ultra-high transparency over a wide range of optical wavelengths.
- The VBG can outperform existing fibre and satellite technologies by three orders of magnitude in terms of attenuation rate, enabling long-range quantum communication over thousands of kilometres.
- The VBG can provide a ground-based, low-loss, high-bandwidth quantum channel that enables novel distributed quantum information applications for computing, communication, and sensing.
- The VBG does not rely on quantum repeaters, which are often used in quantum communication but can suffer from a decrease in communication rate over long distances.
- The VBG can establish a continuous quantum channel connecting remote quantum devices with an ultra-high quantum capacity above 1013 qubits/second over continental scales, significantly higher than other approaches using satellites and quantum repeaters.
- The VBG has the potential to revolutionise quantum networks, enabling a wide range of novel quantum network applications, such as global-scale secure quantum communication, ultra-long-based optical telescopes, quantum network of clocks, quantum data centres, and delegated quantum computing.