The Micius Foundation today named three scientists, including University of New Mexico Distinguished Professor Emeritus Carlton Caves, as recipients of the Micius Quantum Prize 2020 which focuses on the broadly defined field of quantum metrology, recognizing scientific advances ranging from early conceptual contributions to experimental breakthroughs. It is dedicated to promoting quantum information science and technology research.

Caves was recognized for his groundbreaking foundational work on quantum metrology and quantum information theory, especially for elucidating the fundamental noise in interferometers and its suppression with the use of squeezed states.

In addition to Caves, the other laureates were Jun Ye from the University of Colorado and Hidetoshi Katori from the University of Tokyo for their groundbreaking achievements in precision quantum measurements in the development of extremely stable and accurate optical atomic clocks. Each of the recipients will receive a gold medal in honor of the recognition as well as a cash award.

Caves’ citation for the Micius Prize draws attention to a lifetime of work on quantum metrology and quantum information and, particularly, to his explanation of the fundamental noise in interferometry and of how to reduce that noise by using squeezed light. “First, thanks to the Micius Foundation for awarding me this prestigious, international research prize,” said Caves, a Research Professor in the Department of Physics and Astronomy. “The prize is aptly named for the ancient Chinese philosopher Micius, whose moral teachings emphasized introspection, self-reflection, and authenticity, all values that I hold dear, and who taught that all people are equal and that innovation is as valuable as tradition. Second, thanks to the Selection Committee. That this group of outstanding scientists thought that my scientific contributions are worthy of recognition is both gratifying and humbling.”

“Indeed, for now, I want to focus on that lifetime of work, which was carried out with colleagues, postdocs, and Ph.D. students,” said Caves. “We always worked on what we thought was most interesting and most important, with the goal of understanding how the world works. Sometimes we got lucky, and others found our research interesting and important. More often, we weren’t so lucky. This, indeed, is what being a research scientist is all about: you work—or at least I hope you do—on what you find most interesting and most important, with the full knowledge that most of the time, it will turn out that your intense interest is not shared by the research community. 

“To all those who have worked with me throughout my life, thank you. All of you share in this prize. Whether or not we won big with our research, we had the joy of discovery and, just as important, the joy of discovery together. Working with all of you has been one of the chief things that made my life worth living.” 

Caves’ discovery, made in May 1980, was the first to demonstrate that the fundamental noise in interferometry comes from the vacuum (nothing) entering the unused port of an interferometer, and, second, things can be improved by substituting squeezed vacuum in place of the vacuum.

“Light can be put into any interferometer in two ways—two input ports we call them—and one of the input ports is illuminated by a coherent source, always in modern times a laser,” said Caves. “That the fundamental quantum noise comes from the vacuum entering the second, unused port is completely obvious now, but in 1980 it was not understood at all. The conventional understanding in quantum optics was that the noise in interferometry comes from the particulate nature of light—that light is made up of photons—and although this is a perfectly good explanation, like any explanation in quantum physics, it is incomplete and, importantly, it is incomplete in a way that would never lead to the idea of improving things using squeezed light.  

“Indeed, the situation was like reading a detective novel where the author carefully directs attention away from the murder scene. All of quantum optics at this time was, at least on this score, about misdirection. Don’t look at the unused port. There’s nothing there to look at.  Literally nothing. It’s vacuum. No photons. So don’t go there.”

While Caves acknowledges that there were some smarts in figuring this out, a bit of luck was also involved.

“There was also a lot of luck, as accompanies, really, any accomplishment in life,” he said. “Luck to work in a research group, Kip Thorne’s at Caltech, where attention to fundamental questions in quantum measurement was valued and encouraged. Luck to know just enough to realize there is a problem, but not so much as to have absorbed the misdirection of contemporary understanding. Luck to have the luxury of time to work on something of fundamental importance where nobody else was paying attention because the payoff, should there ever be one, was way too far in the future for most physicists to be interested. Luck that the future is now, forty years on, when the use of squeezed light turns out to be of great practical importance as it improves the sensitivity of the LIGO and Virgo laser-interferometer gravitational-wave detectors. Making billion-dollar projects work better—that does attract attention.

“Squeezing of all sorts, in optical, atomic, and optomechanical systems, is now an industry, with applications all over quantum metrology and quantum computation. It is extremely gratifying to think that my ideas on noise in interferometry lit a fuse that is now exploding all over the landscape of quantum technologies.”

The Micius Award

Quantum mechanics, discovered at the beginning of the last century, has been an enormously successful theory of nature and has led to the development of many of today’s most widely used technologies that have completely changed the landscape of society. In past decades, profound progress, made both in the understanding of exploiting quantum superposition and entanglement for new ways of information processing and in the experimental methods of coherent control and interaction of individual quantum particles, has given birth to an emerging field of quantum technologies, also known as the second quantum revolution, which moved beyond the first quantum revolution that simply exploited naturally occurring quantum effects.

The second quantum revolution has been driving and enabling a new generation of classically impossible tasks ranging from unconditionally secure quantum communications, breathtakingly powerful quantum simulation, and quantum computation, to extremely sensitive measurements. To promote the second quantum revolution, a new science foundation, the "Micius Quantum Foundation" was established in 2018 thanks to generous donations from private entrepreneurs.

This Foundation is named after Micius, an ancient Chinese philosopher who lived in a similar period to the Western philosopher Democritus. Micius strongly stood for peace, put forward the concept of "universal love," and performed original scientific work such as the pinhole experiment that proved light traveled straight.