Fascination for quantum weirdness: from naïve questions to fundamental concepts and applications (Orale)

Alain Aspect

Gerardo Adesso, Rosario Lo Franco, Valentina Parigi

Nearing a century since its inception, quantum mechanics is as lively as ever. Its signature manifestations, such as superposition, wave-particle duality, uncertainty principle, entanglement and nonlocality, were long confronted as weird predictions of an incomplete theory, paradoxes only suitable for philosophical discussions, or mere mathematical artifacts with no counterpart in the physical reality. Nevertheless, decades of progress in the experimental verification and control of quantum systems have routinely proven detractors wrong. While fundamental questions still remain wide open on the foundations and interpretations of quantum mechanics, its modern technological applications have captured the fascination of the general public and are having a transformative impact on society. This brief article acts as Introduction to a Special Issue in the Philosophical Transactions of Royal Society A, following from a dedicated Scientific Discussion Meeting where these fascinating topics were explored, giving rise to stimulating debates among speakers and audience. The present issue thus aims at conveying the spirit of those discussions.

Masanori Ohya, Igor Vasil'evich Volovich

Armond Duwell

Quantum Biology, r/Science AMAs

We got interested in the idea that quantum mechanics is involved in biology nearly two decades ago when Johnjoe was puzzling over weird kind of mutations that seemed to become more frequent when they provided an advantage to bacteria, and teamed up with Jim to see if quantum mechanics might provide an explanation. We wrote a paper describing a quantum model for the mutations back in 1999 (http://www.sciencedirect.com/science/article/pii/S0303264799000040) and have since maintained an interest in all aspects of quantum biology. The field exploded about a decade ago when microbes and plants were shown to use quantum coherence in photosynthesis and enzymes were found to use quantum tunnelling to accelerate biochemical reactions. Evidence for quantum effects has since turned up in avian navigation, the sense of smell, even how the mind works. We believe that biology’s connection to the quantum realm provides life with the spark that makes us so different from the inanimate world. To describe this fascinating new field we recently teamed up again to write, ‘Life on the Edge: The Coming of Age of Quantum Biology’. We are here today to talk about our own work and interests in the field of quantum biology but also the fascinating work of our colleagues who have discovered weird quantum effects in such a diverse range of biological activities. We’ll do our best to answer any relevant fundamental quantum or biology questions, such as what is quantum entanglement or how do enzyme work. We are also happy to speculate on how revolutionary quantum biology technologies may be developed from these ground-breaking discoveries. We hope to stimulate interest in what, we believe, is the most exciting emerging science of the 21st century! We will be back at 1 pm ET to answer your questions, ask us anything!

Hippolyte Dourdent

The notion of contextuality, which emerges from a theorem established by Simon Kochen and Ernst Specker (1960-1967) and by John Bell (1964-1966), is certainly one of the most fundamental aspects of quantum weirdness. If it is a questioning on scholastic philosophy and a study of contrafactual logic that led Specker to his demonstration with Kochen, it was a criticism of von Neumann's "proof" that led John Bell to the result. A misinterpretation of this famous "proof" will lead them to diametrically opposite conclusions. Over the last decades, remarkable theoretical progresses have been made on the subject in the context of the study of quantum foundations and quantum information. Thus, the graphic generalizations of Cabello-Severini-Winter and Acin-Fritz-Leverrier-Sainz raise the question of the connection between non-locality and contextuality. It is also the case of the sheaf-theoretic approach of Samson Abramsky et al., which also invites us to compare contextuality with the logical structure of certain classical logical paradoxes. Another approach, initiated by Robert Spekkens, generalizes the concept to any type of experimental procedure. This new form of "universal" contextuality has been raised as a criterion of non-classicality, i.e. of weirdness. It notably led to identify the nature of curious quantum paradoxes involving post-selections and weak measurements. In the light of the fiftieth anniversary of the publication of the Kochen-Specker theorem, this report aims to introduce these results little known to the French scientific public, in the context of an investigation on the nature of the weirdness of quantum physics.