New Source of Quantum Light

This seems quite exciting.   On the list to know more.. 

Researchers Develop New Source of Quantum Light

By MIT News, June 26, 2023

A perovskite nanocrystal.

Using light instead of physical objects as basic qubit units would eliminate the need for complex, expensive equipment to control the qubits and enter and extract data from them.

Credit: Alexander Kaplan et al

Using novel materials that have been widely studied as potential new solar photovoltaics, researchers at MIT have shown that nanoparticles of these materials can emit a stream of single, identical photons.

While the work is currently a fundamental discovery of these materials' capabilities, it might ultimately pave the way to new optically based quantum computers, as well as possible quantum teleportation devices for communication, the researchers say. The results appear today in the journal Nature Photonics, in a paper by graduate student Alexander Kaplan, professor of chemistry Moungi Bawendi, and six others at MIT.

Most concepts for quantum computing use ultracold atoms or the spins of individual electrons to act as the quantum bits, or qubits, that form the basis of such devices. But about two decades ago some researchers proposed the idea of using light instead of physical objects as the basic qubit units. Among other advantages, this would eliminate the need for complex and expensive equipment to control the qubits and enter and extract data from them. Instead, ordinary mirrors and optical detectors would be all that was needed.

From MIT News

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Particles of Light and Fluid Flow

Not quite grokking this,  or its value, but considering it.

Particles of Light May Create Fluid Flow, Data-Theory Comparison Suggests

By Brookhaven National Laboratory

December 20, 2022

This graphic shows the energy density at different times during the hydrodynamic evolution of the matter created in a collision of a lead nucleus (moving to the left) with a photon emitted from the other lead nucleus (moving to the right).

The “elliptic flow” pattern was one of the earliest hints that particle collisions at the Relativistic Heavy Ion Collider could create a quark-gluon plasma.

A computational analysis by scientists at the U.S. Department of Energy's Brookhaven National Laboratory and Wayne State University supports the idea that photons colliding with heavy ions can create a fluid of “strongly interacting” particles.

The researchers found calculations defining such a scheme correlate with data collected by the ATLAS detector at Europe's Large Hadron Collider (LHC).

The calculations are based on the hydrodynamic particle flow observed in head-on collisions of various types of ions at the LHC and the Brookhaven Lab's Relativistic Heavy Ion Collider.

Said Brookhaven Lab's Bjoern Schenke, "For these low energy photon-lead collisions, it is important to run a full 3D hydrodynamic model (which is more computationally demanding) because the particle distribution changes more rapidly as you go out in the longitudinal direction."

From Brookhaven National Laboratory  View Full Article

A Trap for Efficient Light Use

 And thus using it more efficiently.  How well?

Creating a perfect trap for light

by Hebrew University of Jerusalem  and TU Wein    in TechExplore

Whether in photosynthesis or in a photovoltaic system: If you want to use light efficiently, you have to absorb it as completely as possible. However, this is difficult if the absorption is to take place in a thin layer of material that normally lets a large part of the light pass through.

Now, research teams from TU Wien and from The Hebrew University of Jerusalem (HU) have found a surprising trick that allows a beam of light to be completely absorbed even in the thinnest of layers: They built a "light trap" around the thin layer using mirrors and lenses, in which the light beam is steered in a circle and then superimposed on itself—exactly in such a way that the beam of light blocks itself and can no longer leave the system. Thus, the light has no choice but to be absorbed by the thin layer—there is no other way out.

This absorption-amplification method, which has now been presented in the scientific journal Science, is the result of a fruitful collaboration between the two teams: the approach was suggested by Prof. Ori Katz from The Hebrew University of Jerusalem and conceptualized with Prof. Stefan Rotter from TU Wien; the experiment was carried out in by the lab team in Jerusalem and the theoretical calculations came from the team in Vienna.

"Absorbing light is easy when it hits a solid object," shared Prof. Stefan Rotter from the Institute of Theoretical Physics at TU Wien. "A thick black wool jumper can easily absorb light. But in many technical applications, you only have a thin layer of material available and you want the light to be absorbed exactly in this layer."

There have already been attempts to improve the absorption of materials: For example, the material can be placed between two mirrors. The light is reflected back and forth between the two mirrors, passing through the material each time and thus having a greater chance of being absorbed. However, for this purpose, the mirrors must not be perfect—one of them must be partially transparent, otherwise the light cannot penetrate the area between the two mirrors at all. But this also means that whenever the light hits this partially transparent mirror, some of the light is lost.

To prevent this, it is possible to use the wave properties of light in a sophisticated way. "In our approach, we are able to cancel all back-reflections by wave interference", noted HU's Prof. Ori Katz. Helmut Hörner, from TU Wien, who dedicated his thesis to this topic explained, "in our method, too, the light first falls on a partially transparent mirror. If you simply send a laser beam onto this mirror, it is split into two parts: The larger part is reflected, a smaller part penetrates the mirror."  .... ' 

Programmable Matter for Product Design

With a zap of light, system switches objects’ colors and patterns

“Programmable matter” technique could enable product designers to churn out prototypes with ease.

Watch Video  https://news.mit.edu/2021/light-colors-patterns-surface-0504#article-video-inline

Daniel Ackerman | MIT News Office

With Zap of Light, System Switches Objects' Colors, Patterns

MIT News, May 4, 2021

A programmable matter system developed by researchers at the Massachusetts Institute of Technology (MIT) and Russia's Skolkovo Institute of Science and Technology can update imagery on object surfaces rapidly by projecting ultraviolet (UV) light onto items coated with light-activated dye. The ChromoUpdate system's UV light pulse changes the dye's reflective properties, creating colorful new images in minutes. The system’s UV projector can vary light levels across the surface, granting the operator pixel-level control over saturation levels. MIT's Michael Wessley said the researchers are investigating the technology's application to flexible, programmable textiles, "So we could have clothing—t-shirts and shoes and all that stuff—that can reprogram itself."  ..' 

Light Driven 3D Printing

See images at the link.   Improving speed and precision.

Dynamic 3D Printing Process Features Light-Driven Twist

By Northwestern McCormick School of Engineering,   February 12, 2021

Northwestern University engineers developed a method that uses light to improve three-dimensional printing speed and precision.

Researchers at Northwestern University have a developed a three-dimensional (3D) printing technique that uses a liquid photopolymer activated by light and a high-precision robotic arm that allows each layer to be moved, rotated, or dilated as the structure is being built.

Said Northwestern's Cheng Sun, "Now we have a dynamic process that uses light to assemble all the layers but with a high degree of freedom to move each layer along the way.”

The continuous printing process allows 4,000 layers to be printed in about two minutes.

The researchers used their method to 3D-print a customized vascular stent, a soft pneumatic gripper made of one hard and one soft material, a double helix, and a mini Eiffel Tower.

From Northwestern McCormick School of Engineering  ...