Quantum physicists Eric Cavalcanti and Howard Wiseman, of Griffith University, in Queensland, Australia, and colleagues, have been awarded a portion of the prestigious 2023 Paul Ehrenfest Best Paper Award. Cavalcanti and Wiseman were recognised for their FQxI-funded paper, published in Nature Physics in 2020, "A strong no-go theorem on the Wigner's Friend Paradox." You can learn more about the Wigner's friend paradox and the implications of their research in our article Schrödinger's AI Could Test the Foundations of Reality" by George Musser.
The Paul Ehrenfest Best Paper Award for Quantum Foundations was presented by the Austrian Academy of Sciences, at the Institute for Quantum Optics and Quantum Information, in Vienna, Austria. It recognizes outstanding and influential research contributions to the foundations of quantum physics in the past five calendar years. Calvalcanti, Wiseman and their co-authors share the prize with the authors of two other seminal papers on the Wigner's friend paradox that were published in 2018. The first is by FQxI-member, Časlav Brukner, for a paper in Entropy; Brukner's work is also featured in George Musser's article. The second paper appeared in Nature Communications and was written by FQxI's Renato Renner and his colleague Daniel Frauchiger and describes how quantum mechanics cannot consistently describe itself. Renner described their new paradox in an extended edition of the FQxI podcast with Zeeya Merali.
From the award citation:
"In these papers, the authors extend Wigner's famous thought experiment by combining it with aspects of Bell's set-up, thereby constructing a variety of closely related no-go theorems. These theorems challenge the applicability of quantum mechanics to arbitrary physical systems, including macroscopic objects and observers, paired with various assumptions, such as the absoluteness of measurement outcomes or certain locality assumptions, some of which are weaker than those in Bell's theorem or the Kochen-Specker theorem. As a result, these theorems provide new challenges for the interpretation of quantum theory, forcing us to make some hard choices in our conception of quantum reality.
Congratulations to all the winners!