’Solid’ light could compute previously unsolvable problems

Researchers at Princeton University have begun crystallizing light as part of an effort to answer fundamental questions about the physics of matter.

The researchers are not shining light through crystal – they are transforming light into crystal. As part of an effort to develop exotic materials such as room-temperature superconductors, the researchers have locked together photons, the basic element of light, so that they become fixed in place.

“It’s something that we have never seen before,” said Andrew Houck, an associate professor of electrical engineering and one of the researchers. “This is a new behavior for light.”

more…

Geez, that original paper contains a lot of words whose meaning is quite beyond me. I would never have been able to interpret that as crystallising light.

The comments below the link make interesting reading.

That news report makes inferences that the original article (Observation of a Dissipation-Induced Classical to Quantum Transition, in Phys. Rev. X, full article available under a Creative Commons licence here) doesn’t justify. A good, relatively non-technical, summary of the original article is presented with the journal article:

“Our understanding of how large numbers of particles coexist in nature is based on thermodynamics and the underlying theory of statistical mechanics. The simplest case is when the particles do not interact with each other and when the system is in equilibrium, so that its macroscopically observable state does not change with time. However, the world around us is rarely in equilibrium, and most of the dynamical processes we observe occur far from equilibrium and also involve strong interactions. The study of physical systems in this regime encompasses topics of fundamental importance to science, such as dissipation, quantum decoherence, emergence of classicality from intrinsically quantum systems, symmetry breaking, and even how equilibrium is itself established. We apply tools developed for quantum computing to investigate these subjects.

We realize a system of strongly correlated photons, which, when populated with many photons, exhibits classical Josephson oscillations. A loss of photons from the system into the environment leads to a slowing down of the oscillations; at a critical number of photons, the period of the oscillations is seen to diverge, giving rise to a dynamical quantum phase transition far from equilibrium. In contrast with standard expectations, this transition is into a state displaying quantum behavior, namely, the quantum revivals of Schrödinger cat states. This experiment is the first realization of a dissipative quantum simulator built using standard solid-state fabrication technologies.

Our findings open new directions for future studies of strongly correlated many-body physics using photons, where dissipation is both central and well controlled. We expect that our results will have broad implications in fields such as condensed matter physics.”