Quantum researcher Leo Kouwenhoven leaves Microsoft

Physics professor Leo Kouwenhoven has left Microsoft. The American tech company confirms that NRC after a message in de Volkskrant† Since 2016, Kouwenhoven has been working on a quantum computer for Microsoft. At the beginning of last year, a research group led by Kouwenhoven withdrew a scientific publication due to problems with data processing. It is unclear whether Kouwenhoven’s departure from Microsoft has to do with this.

Quantum computers potentially have enormous computing power. Tech companies Google and IBM already have a working quantum computer. It is still under development at Microsoft.

The American company was enthusiastic about Kouwenhoven’s quantum computer research. The Delft professor tried to confirm the existence of majorana particles in nanowires. Those particles could be used as qubits (bits that a quantum computer uses for calculations). According to theorists, majorana particles exist, but there is as yet no experimental evidence for this.

Quantum lab

In 2016, Kouwenhoven became director of a new lab on the TU Delft campus, where Microsoft’s quantum computer is being developed. Kouwenhoven has left Microsoft since this month. „This is related to a change in the approach to scalable quantum computing,” a Microsoft spokesperson emailed. “We wish Leo every success for the future and thank him for his time at Microsoft.”

Kouwenhoven’s research has been under discussion since last year. In 2012, he published the first tentative evidence for the existence of the majorana particle. In 2018 he wrote in a new study in magazine Nature that, thanks to improved research materials, he had now certainly found it. That was world news. But last February, the 2018 publication was withdrawn. The reason for this was that the researchers at the time had not stated that only part of the data confirmed the finding of majoranas. There are now also doubts about other studies of his department. Last February, a TU Delft integrity committee started a second investigation to the way in which the researchers processed the data.

Are these problems surrounding the investigation the reason for Kouwenhoven’s departure from Microsoft? The company spokesperson declined to comment. Kouwenhoven himself could not be reached for comment.

Team from Copenhagen

Another Microsoft team in Copenhagen claimed start of this week to have taken a step in their search for the marjoram particle. That team uses a different approach than Kouwenhoven’s team. “Microsoft may be setting a new course with other researchers at the helm,” Carlo Beenakker said over the phone. He is a physicist at Leiden University. “That has nothing to do with Kouwenhoven’s work.”

In recent years, Kouwenhoven was professor of physics at TU Delft without appointment. That is, he was not paid by the university. That situation has not changed, QuTech informed NRC† QuTech is the quantum institute of TU Delft and TNO. Kouwenhoven supervises twelve PhD students at QuTech. He continues that.