Draft:Microsoft Azure Quantum

Microsoft Azure Quantum (Azure Quantum) is part of Microsoft’s Strategic Mission and Technologies division focusing on scientific discovery across high-performance computing, artificial intelligence and quantum computing applications with an early emphasis on chemistry and materials science. Microsoft Azure Quantum is also the name for the company’s cloud service that provides access to quantum and hybrid HPC-quantum services across multiple hardware modalities. The Azure Quantum team uses a platform approach to quantum computing that includes original research, quantum networks, and software and hardware development. Azure Quantum Elements combines AI and HPC to provide a “workbench for scientific computing,” specifically quantum chemistry and materials science research. The team also has developed a quantum programming language – Q# (pronounced Q Sharp) and an Azure Quantum Development Kit.

In 2024, Azure Quantum, along with hardware partner Quantinuum, created four logical qubits from 30 physical qubits on trapped ion hardware using a quantum error correction code. With this accomplishment, the platform offered the most logical qubits available across quantum computing platforms, with 14,000 error-free experiments and an error rate 800x better than physical qubits alone.

Microsoft is the only major technology company with a history of research and development in topological quantum computing.

History
In 2000, physicist Alexei Kitaev at Microsoft Research proposed the idea of using Majorana particles for topological quantum computing. Microsoft has pursued this approach since 2004.

In 2003, Michael Freedman, who would go on to lead Microsoft’s quantum research at Station Q in 2005, authored a paper with Kitaev demonstrating how a topological quantum computer could perform any computation that a conventional quantum computer could.

In 2005, Das Sarma, Freedman and Chetan Nayak proposed creating a topological qubit using the fractional quantum Hall effect. Nayak took on the role of general manager for Microsoft’s quantum hardware program the same year. In 2006 and 2008, the team continued with publication of papers using non-abelian anyons for topological quantum computing. In 2012, evidence was found supporting the creation and detection of Majorana quasiparticles in a paper from future Microsoft researcher Leo Kouwenhoven. In 2015, Microsoft further developed the theoretical framework of Majorana zero modes for information processing through braiding-based topological quantum computing.

In 2017, Microsoft released Q#, a programming language for quantum algorithms, as part of its quantum development kit.

In March 2021, Kouwenhoven’s team at Delft University of Technology published a retraction note in the journal Nature about a paper published in 2018 that had claimed the definitive existence of Majorana particles. The team admitted the data had been overly corrected to suggest the appearance of the particle. An investigation at the university concluded that that the researchers did not intend to mislead but were caught up in the excitement of the work.

Microsoft’s Azure Quantum platform was officially released for public preview in February 2021 as part of Microsoft’s Strategic Missions and Technologies division, which focuses on commercializing emerging technologies across quantum computing, telecommunications, space, satellites, cloud and digital transformation.

In December 2021, Krysta Svore, a Distinguished Engineer at Microsoft, took on the role of vice president of quantum software.

In March 2022, Matthias Troyer, a Distinguished Scientist and Technical Fellow at Microsoft, joined the quantum system architecture and quantum application development to lead these efforts.

In 2023, Azure Quantum Elements was released to accelerate scientific discovery in computational chemistry by scaling and speeding up molecular simulations and calculations using HPC, AI and quantum computing.

The same year, the Azure Quantum team demonstrated the ability to create and control Majorana quasiparticles, the qubits in Microsoft’s topological quantum computer.

At the end of 2023, the team outlined three quantum computing implementation levels (QCIL), starting at a foundational level with noisy physical qubits, progressing to a resilient state with reliable logical qubits and finally achieving scale with quantum supercomputers.

In 2024, in collaboration with Quantinuum, Microsoft achieved the resilient level of quantum implementation on a trapped ion system by creating 4 logical qubits from 30 physical qubits.

Hardware
Microsoft offers cloud access to quantum computing with the most logical qubits available, asserting in 2024 that its error correction algorithm on a trapped ion processor from Quantinuum demonstrated the best ratio of reliable logical qubits to physical qubits on a quantum chip ever produced, up to 800 times better than previous records.

Azure Quantum cloud-based software supports other quantum hardware modalities, including neutral atom and superconducting systems.

Topological quantum computing
The Azure Quantum team is building a topological quantum computer from Majorana particles, also known as Majorana zero modes. The qualities of these modes could potentially make qubits faster, smaller and more accurate than other quantum computing approaches by offering inherent protection against errors.

Microsoft’s ideas for a topological quantum computer were first proposed in 2005, and the first prerequisite for topological quantum computing by Majorana zero modes was achieved in 2023, when Microsoft engineered devices to induce and control a topological phase creating Majorana zero modes.

Majorana zero modes allow a qubit to be split into two parts, protecting the encoded information from local disturbances. The neutral charge of the particle also means no energy difference exists in Majorana zero modes between its two possible states, making them more stable and less prone to environmental disturbances than other qubit types.

In 2022, Microsoft demonstrated the underlying physics required to build scalable topological qubits with Majorana particles. The topological gap protocol creates and sustains a topological quantum phase of matter bookended by a pair of Majorana zero modes.

Microsoft’s process layers semiconducting and superconducting materials onto a device in an extremely controlled and atomically precise way. In the presence of specific magnetic fields and voltages, the devices can produce a topological phase with a pair of Majorana zero modes.

In 2022, the Microsoft Azure Quantum team demonstrated the ability to create and control Majorana quasiparticles. The paper published in 2023 presented measurements and simulations of semiconductor-superconductor heterostructure devices that are consistent with the observation of topological superconductivity and Majorana zero modes.

The topological gap protects quantum information against interaction with the environment, a key differentiator between Microsoft’s hardware platform and those that have merely demonstrated non-Abelian anyons in software systems.