Microsoft claims breakthrough in quantum computing system • The Register

Microsoft has claimed a significant breakthrough in its journey to build and operate a viable quantum computer.

The Windows giant said on Monday it was able to create the right circumstances in which it could sustain its version of a quantum bit, which it calls a “topological qubit.”

Like all organizations claiming the superiority of quantum computing, Microsoft has argued that its qubit is a stepping stone to a “quantum computer that should be more stable than machines built with other known types of qubits, and therefore evolve as no other”.

Microsoft also said its qubit topology breakthrough is the next step toward creating a million-qubit quantum computer, a step that many agree is a minimum specification needed to solve large-scale problems not possible on classical computers. today.

The computing giant takes several approaches to quantum computing. One is to build futuristic quantum computers based on quasi-particles that have existed in theory. Microsoft has also hired renowned academics to solve challenges in physics to create topological quantum computers.

Meanwhile, Microsoft’s venture capital arm is backing faster quantum approaches by funding companies like PsiQuantum, which hopes to build a data center-sized error-corrected system in the coming years. .

Correction of errors

Microsoft released the thinking behind its topological quantum computer in 2007; the technology uses quasi-particles called non-abelian anyons, which at the time only existed in theory. In 2015, Microsoft published a description of abelian processors suitable for computations in quantum systems.

It was hoped that non-Abelion anyons could be used to build a quantum computing system that does not need error correction to function. Generally speaking, qubits are fragile and subject to interference from matter and electromagnetic radiation which can ruin calculations. Microsoft’s approach is to avoid this and eliminate the need for error correction by creating a qubit with “built-in protection against environmental noise, which means it should take far fewer qubits to perform useful calculations. and fix mistakes,” the biz said.

The supposed breakthrough announced on Monday is the next iteration of bringing a topological quantum computer from theory to the real world. The Redmond researchers said they succeeded in creating zero Majorana modes at the ends of a nanowire, which creates a protective layer for the qubit and enables computational operations.

“The only way to unlock quantum information is to look at the combined state of Majorana’s two zero modes at the same time. Taking these steps strategically both enables quantum operations and creates inherent protection for the qubit,” said writes Microsoft’s Jennifer Langston. .

The research team has already seen the signature at one end of the wire, but needed to see it at both ends to create a workable system on which to build their topological quantum systems.

Microsoft has successfully tuned Majorana zero modes to the topological phase by using an exotic material and developing a process that layers semiconductor and superconductor materials on a device.

“In the presence of specific magnetic fields and voltages, the devices can produce a topological phase with a pair of Majorana zero modes – characterized by telltale energy signatures that will appear at either end of a nanowire under the right conditions – and a gap measurable topology,” Microsoft’s Langston wrote.

It’s just a breakthrough in a long road ahead for Microsoft, whose physicists are still establishing concepts around anyons, which are considered quasiparticles beyond standard fermions and bosons. .

The use of superconducting material indicates that the system will need cryogenic cooling, which is typically measured below minus 180 degrees Celsius or minus 292 degrees Fahrenheit. Microsoft is working with companies like Rambus on cooling technologies for quantum components. ®

Gordon K. Morehouse