Another publication of high-profile quantum researcher Leo Kouwenhoven has been retracted. The authors have determined that data in the 2017 Nature paper investigating nanowire networks as breeding grounds for so-called Majorana particles had been “inappropriately deleted or cropped.” This manipulation affected the agreement between theoretical prediction and experimental results, voiding the claim that Majorana particles can travel unencumbered through the nanomaterial.
Kouwenhoven built a career on Majoranas, considered to be the holy grail for quantum computing thanks to their extraordinary stability. A recipient of the Spinoza Prize, the highest scientific award in the Netherlands, the TU Delft professor led the Qutech quantum research institute before moving to Microsoft’s new quantum lab on the same campus (link in Dutch).
Last year, however, Kouwenhoven’s landmark 2018 Majorana paper was retracted after similar problems with raw data processing had been detected. A TU Delft investigation concluded that there was no malicious intent, only negligence. This year, another investigation was launched following allegations that more papers from Kouwenhoven’s group contain errors. That inquiry is still ongoing.
Last month, Kouwenhoven stepped down as the director of the Microsoft Quantum Lab. This bore no relation to the first retracted paper, he told NRC Handelsblad. Kouwenhoven still teaches at TU Delft, without remuneration.