Microsoft Majorana 1
Microsoft today said its new quantum chip is the first to be powered by a new Topological Core architecture that “will realize quantum computers capable of solving meaningful, industrial-scale problems in years, not decades.”
Majorana 1 leverages the first topoconductor, a material that can observe and control Majorana particles to produce more reliable and scalable qubits, which are the building blocks for quantum computers, according to Microsoft.
The company said topoconductors and the new type of chip they enable offer a path to developing quantum systems that can scale to a million qubits and are capable of tackling the most complex industrial and societal problems, Microsoft said.
“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 Chetan Nayak, Microsoft technical fellow. “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 company said the news validates Microsoft’s choice years ago to pursue a topological qubit design, the company said. Today, the company has placed eight topological qubits on a chip designed to scale to 1 million.
“From the start we wanted to make a quantum computer for commercial impact, not just thought leadership,” said Matthias Troyer, Microsoft technical fellow. “We knew we needed a new qubit. We knew we had to scale.”
That approach led the Defense Advanced Research Projects Agency (DARPA), a federal agency that invests in technologies important to national security, to include Microsoft in a program to evaluate whether new quantum computing technologies could build commercially relevant quantum systems faster than believed possible.
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) program – one of the programs that makes up DARPA’s larger Quantum Benchmarking Initiative – which aims to deliver the industry’s first utility-scale fault-tolerant quantum computer, or one whose computational value exceeds its costs.
The architecture used to develop the Majorana 1 processor offers a path to fit a million qubits on a single chip that can fit in the palm of one’s hand, Microsoft said. This is a needed threshold for quantum computers to deliver transformative, real-world solutions – such as breaking down microplastics into harmless byproducts or inventing self-healing materials for construction, manufacturing or healthcare. All the world’s current computers operating together can’t do what a one-million-qubit quantum computer will be able to do.
“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.”
The topoconductor, or topological superconductor, is a special category of material that can create an entirely new state of matter – not a solid, liquid or gas but a topological state. This is harnessed to produce a more stable qubit that is fast, small and can be digitally controlled, without the tradeoffs required by current alternatives. A new paper published Wednesday in Nature outlines how Microsoft researchers were able to create the topological qubit’s exotic quantum properties and also accurately measure them, an essential step for practical computing.
This required developing a new materials stack made of indium arsenide and aluminum, much of which Microsoft designed and fabricated atom by atom. The goal was to coax new quantum particles called Majoranas into existence and take advantage of their unique properties to reach the next horizon of quantum computing, Microsoft said.
Micosoft said the Topological Core powering the Majorana 1 is reliable by design, incorporating error resistance at the hardware level making it more stable.
Commercially important applications will also require trillions of operations on a million qubits, which would be prohibitive with current approaches that rely on fine-tuned analog control of each qubit. The Microsoft team’s new measurement approach enables qubits to be controlled digitally, redefining and vastly simplifying how quantum computing works.
Because they can use quantum mechanics to mathematically map how nature behaves with high precision – from chemical reactions to molecular interactions and enzyme energies – million-qubit machines could solve certain types of problems in chemistry, materials science and other industries that are impossible for today’s classical computers to accurately calculate.
The quantum world operates according to the laws of quantum mechanics, which are not the same laws of physics that govern the world we see. The particles are called qubits, or quantum bits, analogous to the bits, or ones and zeros, that computers now use.
Krysta Svore, Microsoft technical fellow (image: John Brecher for Microsoft)
Microsoft said the Nature paper marks peer-reviewed confirmation that Microsoft has not only been able to create Majorana particles, which help protect quantum information from random disturbance, but can also reliably measure that information from them using microwaves.
Majoranas hide quantum information, making it more robust, but also harder to measure. The Microsoft team’s new measurement approach is so precise it can detect the difference between one billion and one billion and one electrons in a superconducting wire – which tells the computer what state the qubit is in and forms the basis for quantum computation.
The measurements can be turned on and off with voltage pulses, like flicking a light switch, rather than finetuning dials for each individual qubit. This simpler measurement approach that enables digital control simplifies the quantum computing process and the physical requirements to build a scalable machine.
Microsoft’s topological qubit also has an advantage over other qubits because of its size, according to the company. Even for something that tiny, there’s a “Goldilocks” zone, where a too-small qubit is hard to run control lines to, but a too-big qubit requires a huge machine, Troyer said. Adding the individualized control technology for those types of qubits would require building an impractical computer the size of an airplane hangar or football field.
Majorana 1, Microsoft’s quantum chip that 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 datacenters.
“It’s one thing to discover a new state of matter,” Nayak said. “It’s another to take advantage of it to rethink quantum computing at scale.”
Microsoft’s topological qubit architecture has aluminum nanowires joined together to form an H. Each H has four controllable Majoranas and makes one qubit. These Hs can be connected, too, and laid out across the chip like so many tiles.
“It’s complex in that we had to show a new state of matter to get there, but after that, it’s fairly simple. It tiles out. You have this much simpler architecture that promises a much faster path to scale,” said Krysta Svore, Microsoft technical fellow.
The quantum chip doesn’t work alone. It exists in an ecosystem with control logic, a dilution refrigerator that keeps qubits at temperatures much colder than outer space and a software stack that can integrate with AI and classical computers. All those pieces exist, built or modified entirely in-house, she said.
To be clear, continuing to refine those processes and getting all the elements to work together at accelerated scale will require more years of engineering work. But many difficult scientific and engineering challenges have now been met, Microsoft said.
Getting the materials stack right to produce a topological state of matter was one of the hardest parts, Svore added. Instead of silicon, Microsoft’s topoconductor is made of indium arsenide, a material currently used in such applications as infrared detectors and which has special properties. The semiconductor is married with superconductivity, thanks to extreme cold, to make a hybrid.
“We are literally spraying atom by atom. Those materials have to line up perfectly. If there are too many defects in the material stack, it just kills your qubit,” Svore said.
“Ironically, it’s also why we need a quantum computer – because understanding these materials is incredibly hard. With a scaled quantum computer, we will be able to predict materials with even better properties for building the next generation of quantum computers beyond scale,” she said.
