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DARPA selects Microsoft to continue the development of a utility-scale quantum computer 

United States Government renews funding to Microsoft Azure Quantum based on recent results and detailed plans for building a quantum computer.

A program run by the Defense Advanced Research Projects Agency (DARPA) aims to determine the feasibility of constructing and operating a utility-scale quantum computer, which would be capable of reliably and accurately solving meaningful problems that are prohibitive on classical computers. This program, known as the Underexplored Systems for Utility-Scale Quantum Computing (US2QC), invests in companies that are using promising, innovative approaches in their efforts to design and build a functional, scalable quantum computer. Recently, Microsoft Azure Quantum was selected by DARPA for continued support in the development of a utility-scale quantum computer based on topological qubits.  

We are looking forward to extending our collaboration with DARPA as we continue to make progress in the design and validation of a scalable quantum computer. Having successfully completed the first phase, which involved providing a detailed explanation of Microsoft Azure Quantum’s technology to DARPA, we will now focus our efforts on designing a prototype of a topological quantum computer.

—Dr. Chetan Nayak, Technical Fellow and Distinguished Engineer, Microsoft Azure Quantum hardware team. 

Quantum computing

Researchers in the field of quantum computing aim to harness the power of nature to drastically accelerate scientific discovery, allowing for exceptionally complex problems to be solved. For example, quantum computing could serve as a tool to help researchers discover novel materials that mitigate climate change or advance clean-energy solutions. However, designing and building a utility-scale quantum computer remains extremely challenging due to the scientific and engineering breakthroughs required. 

Quantum computers use quantum bits known as qubits to encode information, and those qubits are prone to errors, which are compounded when scaled. To address this issue, Microsoft Azure Quantum is designing a fault-tolerant quantum computer based on topological qubits, which are qubits with built-in error protection. The unique scalability of topological qubits is due to three important characteristics—they are small, fast, and able to be controlled digitally.   

Microsoft expects that a computer built with topological qubits will scale to the level at which it can solve commercially significant problems far too complex for classical computers, such as those in chemistry and materials science. This ability to reach utility scale is possible because topological qubits can process information much faster than other types of qubits can. Furthermore, a topological quantum computer could control over one million physical qubits on a single chip, which is enough to perform extremely complex computations in a practical timeframe, yet the computer itself would be small enough to fit in a closet.    

A fault-tolerant quantum computer would have an advantage over classical computers when it became capable of performing millions of reliable quantum operations per second (rQOPS), which is a new industry metric that represents a quantum computer’s ability to solve real problems. A quantum computer with that capability would produce, at most, one error for every trillion operations. Existing quantum computers have an rQOPS of zero because they operate with qubits that are unreliable and noisy, meaning that they are susceptible to environmental conditions. 

Azure Quantum

Azure Quantum

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Microsoft’s topological approach 

When presented with a variety of proposed technologies, Microsoft’s topological approach was selected by DARPA for continued investment. The review process that led to Microsoft’s selection was conducted not only by DARPA but also by experts at the Air Force Research Laboratory, Johns Hopkins University Applied Physics Laboratory, Los Alamos National Laboratory, Oak Ridge National Laboratory, and the NASA Ames Research Center. The breakthroughs already achieved by the Microsoft Azure Quantum team, along with hardware and software designs, plans for sourcing materials, and detailed risk management strategies, helped solidify support from DARPA to continue evaluating Microsoft’s research toward building a quantum computer. 

The topological gap reduces the effects of environmental noise on topological qubits, making them stable.

As the collaboration between DARPA and Microsoft progresses to the next phase, the Microsoft Azure Quantum team will develop a detailed design for a Fault-Tolerant Prototype (FTP) of a quantum computer based on topological qubits. The design for the FTP will identify the minimum performance requirements for all components and subsystems of this small-scale quantum computer, thus demonstrating the feasibility of building and operating a utility-scale quantum computer.  

Microsoft’s FTP is intended to process information stored in multiple logical qubits, representing thousands of physical qubits, which would establish a baseline for a scalable quantum computer. DARPA will be provided with the architectural designs for the FTP, which will be evaluated by technical experts on DARPA’s test and evaluation team. Additionally, the scientific discoveries made by Microsoft during this process will be independently verified by DARPA in Microsoft’s facilities. 

Microsoft views DARPA’s decision to extend its investment in Microsoft Azure Quantum as lending confidence to the challenging but promising topological approach and to Microsoft’s ability to design and build a scaled quantum supercomputer. The achievement of this goal will allow for currently intractable problems to be solved quickly, bringing tremendous value to the world. 

Stay informed on Microsoft’s advancements in quantum computing 

To hear directly from Microsoft Azure Quantum’s scientists and leaders in the quantum computing field, tune in to the Microsoft Quantum Innovator Series. There, you can learn more about quantum computing and be among the first to hear about Microsoft’s breakthroughs on the path to building a scalable quantum computer. 

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