Qubits put into reverse

A group of scientists at the Niels Bohr Institute (NBI), University of Copenhagen, has figured out how to make spin qubits perform controlled backward rotations. This has never been shown before – and the journal Physical Review Letters, where the research has just been published, highlights the innovative discovery in the category "Editor's Suggestion."

"I guess you can say that we have figured out how to run the qubits in both forward and reverse gear – under certain circumstances," says Ph.D. Filip Malinowski, Center for Quantum Devices (QDev) at the Niels Bohr Institute.

Malinowski and QDev colleague Frederico Martins – who is now with the University of New South Wales, Australia – spearheaded the 'reverse project' which also included scientists from Purdue University, USA. The American scientists' role involved the production of extremely pure semiconductor crystals, which the NBI team needed as a foundation to build upon when putting together the specific 'environment' needed to force qubits into reverse.