Nobel Prize in physics recognizes three for achievements in Quantum Photonics

The 2022 Nobel Prize in physics has been awarded to Alain Aspect, John F. Clauser, and Anton Zeilinger. The trio will share the prize “for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science.”

Aspect, professor at Université Paris-Saclay and École Polytechnique; Clauser, research physicist at J.F. Clauser and Associates; and Zeilinger, professor at the University of Vienna, were awarded the prize by the Royal Swedish Academy of Sciences. According to Optica, following the announcement of the winners, the trio’s separate but related research employed practical experiments on entangled quantum states, laying the foundation for the emergence of quantum technology.

Aspect is an Optica honorary member, Clauser is an Optica emeritus member, and Zeilinger is an Optica fellow.

(Left to right) Alain Aspect, John F. Clauser, and Anton Zeilinger were awarded the 2022 Nobel Prize in physics for their work in quantum photonics. Courtesy of Niklas Elmehed, Nobel Prize Outreach

“Drs. Aspect, Clauser, and Zeilinger established the quantum property of entanglement, and we celebrate the Nobel Foundation selection for their work in quantum optics,” said Satoshi Kawata, 2022 president of Optica and emeritus professor at Osaka University.

The three pioneered early experiments, he continued, demonstrating that “quantum particles could be linked or entangled, such that the random behavior of one is tied to the behavior of the others much more strongly than seems intuitively possible.”

For a long time, according to the Royal Swedish Academy of Sciences, a question existed about whether the correlation was because the particles in an entangled pair contained hidden variables, instructions that tell them which result they should give in an experiment. In the 1960s, John Stewart Bell developed the mathematical inequality that is named after him. This states that if there are hidden variables, the correlation between the results of a large number of measurements will never exceed a certain value. However, quantum mechanics predicts that a certain type of experiment will violate Bell’s inequality, thus resulting in a stronger correlation than would otherwise be possible.

According to the academy, Clauser developed Bell’s ideas, to a practical experiment. Measurements obtained by Clauser supported quantum mechanics by clearly violating a Bell inequality. This meant that quantum mechanics cannot be replaced by a theory that uses hidden variables.

John Clauser, experimental and theoretical physicist. Courtesy of Peter Lyons, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons.

Some loopholes remained after Clauser’s experiment. Aspect developed the setup, using it in a way that closed an important loophole. He was able to switch the measurement settings after an entangled pair had left its source, so the setting that existed when they were emitted could not affect the result.

Using refined tools and long series of experiments, Zeilinger started to use entangled quantum states. Among other demonstrations, his research showed a phenomenon called quantum teleportation, which makes it possible to move a quantum state from one particle to one at a distance.

“It has become increasingly clear that a new kind of quantum technology is emerging. We can see that the laureates’ work with entangled states is of great importance, even beyond the fundamental questions about the interpretation of quantum mechanics,” said Anders Irbäck, chair of the Nobel Committee for Physics.

Aspect received the 1999 Max Born Award, 2011 Herbert Walther Award, and 2013 Frederic Ives Medal/Jarus W. Quinn Prize from Optica. Other awards include the CNRS Gold Medal (2005), Wolf Prize in Physics (2010), Niels Bohr Gold Medal and the UNESCO-Niels Bohr Gold Medal (2013), and the Balzan Prize in Quantum Information (2013). In 2014, he was named Officier de la Légion d’Honneur, the highest French order of merit.

Alain Aspect. Courtesy of École polytechnique Université Paris-Saclay, CC BY-SA 2.0 https://creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons.

Clauser is known for his contributions to the foundations of quantum mechanics, in particular for the Clauser-Horne-Shimony-Holt (CHSH) inequality, the first experimental proof that nonlocal quantum entanglement is real (Freedman-Clauser), and for the formulation of the theory of local realism (Clauser-Horne).

Clauser proposed atom interferometers as useful ultrasensitive inertial and gravity sensors, and patented the devices. In 1998, he invented and patented the use of the Talbot-Lau interferometry for “Ultrahigh Resolution Interferometric X-ray Imaging.” This invention, in turn, allowed x-ray phase-contrast medical imaging of soft tissue. Clauser was awarded the Reality Foundation Prize in 1982, the Wolf Prize in 2010, and the 2011 Thompson-Reuters Citation Laureate in Physics.

Zeilinger pioneered quantum mechanics through theoretical and experimental work on entanglement, most notably his demonstration of quantum teleportation in 1997. In 1998, was also the first to experimentally demonstrate entanglement swapping — the teleportation of an entangled state between qubits, a critical mechanism for quantum computation networks

Anton Zeilinger, professor of physics emeritus at the University of Vienna. Courtesy of Jaqueline Godany, CC BY 4.0 https://creativecommons.org/licenses/by/4.0, via Wikimedia Commons.

Zeilinger was awarded the inaugural Isaac Newton Medal of the Institute of Physics in 2008 recognizing “his pioneering conceptual and experimental contributions to the foundations of quantum physics, which have become the cornerstone for the rapidly evolving field of quantum information.” He received the Wolf Prize in 2010 and the Cozzarelli Prize from the National Academy of Sciences in 2019.