Researchers from the SNI network have presented a method that allows them not only to control quantum states more easily but also to keep them stable for longer. To this end, they rotate the magnetic field in a semiconducting nanowire that contains individual electrons acting as quantum bits. Led by Professor Christian Schönenberger (Department of Physics, University of Basel), the team recently published their results in Communications Physics. The findings could help to drive forward the development of a reliable and scalable quantum computer.

Quantum computers have the potential to solve problems that cannot be tackled by even the most powerful supercomputers available today. These enhanced capabilities could, for example, pave the way for the development of new therapeutics.

The basic units of today’s prototype quantum computers are known as quantum bits (“qubits” for short). In order to develop reliable and scalable quantum computers, it is vital to create quantum bits that maintain a stable quantum state for as long as possible — which corresponds to the storage time — while also allowing effective control and manipulation.

For investigations of this kind, the group led by Professor Christian Schönenberger (Department of Physics, University of Basel) created qubits using individual electrons in superconducting nanowires. They also explored ways of improving the qubits’ application in scalable quantum computers.

 “We analyzed the electrons using a superconducting electrical circuit that oscillates at microwave frequencies. In the process, we managed to improve the controllability and storage time of the electrons,” report the two first authors, Dr. Alessia Pally and Dr. Jann Ungerer. “The remarkable feature is that we were able to improve both at the same time because quantum systems are generally more vulnerable to noise when they are easier to control,” adds Ungerer, who carried out this work as part of his doctoral dissertation at the Swiss Nanoscience Institute of the University of Basel.

Original publication:

A dephasing sweet-spot with enhanced dipolar coupling
Jann H. Ungerer, Alessia Pally, Stefano Bosco, Artem Kononov, Deepankar Sarmah, Sebastian Lehmann, Claes Thelander, Ville F. Maisi, Pasquale Scarlino, Daniel Loss, Andreas Baumgartner & Christian Schönenberger
Communications Physics volume 8, Article number: 306 (2025)
https://doi.org/10.1038/s42005-025-02216-9