Inside Microsoft’s new transistor for the quantum age
Cette publication existe aussi en Français
Microsoft has thrown a new material into the mix for a scalable quantum processor with millions of fault tolerant qubits in what it calls a transistor for the quantum age.
The Majorana 1 uses a ‘topoconductor’, a material that can observe and control Majorana quasiparticles to produce more reliable and scalable qubits. Microsoft describes this as a breakthrough, as these quasiparticles have not yet been formally identified..
Majorana particles consist of both itself and antiparticle and the architecture can scale to a million qubits, says the company. A stack of superconducting indium arsenide and aluminium nanowires, much of which Microsoft designed and fabricated atom by atom, creates the Majorana quasiparticles at a temperature below 10K (-263 °C).
A paper published in Nature outlines the measurement of the topological qubit’s exotic quantum properties. However Nature points out it doesn’t prove the existence of the quasiparticles, and a Microsoft team at TU Delft retracted a paper detailing the technology in 2021. “It’s one thing to discover a new state of matter,” said Chetan Nayak, Microsoft technical fellow. “It’s another to take advantage of it to rethink quantum computing at scale.”
The topological qubit architecture has aluminium nanowires joined together to form an H. Each H has four controllable Majorana quasiparticles and makes one qubit. These Hs can be connected, too, and laid out across the chip in tiles.
The structure of the Majorana qubit
“We took a step back and said ‘OK, let’s invent the transistor for the quantum age. What properties does it need to have?’” said Nayak. “And that’s really how we got here – it’s the particular combination, the quality and the important details in our new materials stack that have enabled a new kind of qubit and ultimately our entire architecture.”
The Majorana 1 chip contains both qubits as well as surrounding control electronics, can be held in the palm of one’s hand and fits neatly into a quantum computer that can be easily deployed inside Azure datacentres.
“Whatever you’re doing in the quantum space needs to have a path to a million qubits. If it doesn’t, you’re going to hit a wall before you get to the scale at which you can solve the really important problems that motivate us,” Nayak said. “We have actually worked out a path to a million.”
This is similar to the topological qubits being developed by D-Wave as detailed in eeNews Europe.
“This is truly an advance for the industry: building a custom chip that uses topological qubits which many consider extremely useful for scaling to powerful quantum computers. The announcement reinforces our assessment that fault-tolerant quantum hardware is closer than many business leaders think,” said Markus Pflitsch, founder and CEO of Swiss quantum developer Terra Quantum.
The Microsoft Majorana-1 quantum processor
The architecture enables qubits to be controlled digitally, vastly simplifying the design of a large machine.
Microsoft is now one of two companies to be invited to move to the final phase of DARPA’s Underexplored Systems for Utility-Scale Quantum Computing (US2QC) programme, one of the programmes that makes up DARPA’s larger Quantum Benchmarking Initiative.
Microsoft has already partnered with Quantinuum and Atom Computing on current qubit technologies such as trapped ions in its Azure cloud service.
If you enjoyed this article, you will like the following ones: don't miss them by subscribing to :
