Structured Light...

This image shows the creation of hybrid entangled photons by combining polarization with a "twisted" pattern that carries orbital angular momentum. Credit: Forbes and Nape

Topics: Electrical Engineering, Electromagnetic Radiation, Quantum Computing, Quantum Electrodynamics, Quantum Mechanics

Structured light is a fancy way to describe patterns or pictures of light, but deservedly so as it promises future communications that will be both faster and more secure.

Quantum mechanics has come a long way during the past 100 years but still has a long way to go. In AVS Quantum Science researchers from the University of Witwatersrand in South Africa review the progress being made in using structured light in quantum protocols to create a larger encoding alphabet, stronger security and better resistance to noise.

"What we really want is to do quantum mechanics with patterns of light," said author Andrew Forbes. "By this, we mean that light comes in a variety of patterns that can be made unique—like our faces."

Since patterns of light can be distinguished from each other, they can be used as a form of alphabet. "The cool thing is that there are, in principle at least, an infinite set of patterns, so an infinite alphabet is available," he said.

Traditionally, quantum protocols have been implemented with the polarization of light, which has only two values—a two-level system with a maximum information capacity per photon of just 1 bit. But by using patterns of light as the alphabet, the information capacity is much higher. Also, its security is stronger, and the robustness to noise (such as background light fluctuations) is improved.

"Patterns of light are a route to what we term high-dimensional states," Forbes said. "They're high dimensional, because many patterns are involved in the quantum process. Unfortunately, the toolkit to manage these patterns is still underdeveloped and requires a lot of work."

Structured light promises path to faster, more secure communications
American Institute of Physics, Phys.org

5G Caveat Emptor...

New 5G antennas (left) are smaller than 4G ones (right). Upcoming 5G networks will use higher-frequency radio spectrum, which will provide more bandwidth and enable the faster data-transfer rates that new technologies, such as autonomous vehicles, smart energy grids, and internet-of-things devices, will demand. (Photos by KPhrom/Shutterstock.com.)

Topics: Electromagnetic Radiation, Mathematics, Stochastic Modeling, Research, Satellite, Weather

The fight is on over 5G. Telecommunication companies and the US government promote the latest mobile broadband because it will provide faster data-transfer rates than the current broadband communication standard. Faster, more reliable digital communication is needed for the newest technologies—autonomous vehicles, internet-of-things devices, and smart energy grids, among others. But meteorologists, US science agencies, and other countries worry that strong 5G signals, if not properly regulated, may interfere with satellites that are crucial to weather forecasting.

Today’s 4G network, nearly a decade old, moves data by bouncing radio waves between cell towers and devices such as smartphones. A 5G network would operate similarly but use a wider frequency range and more bandwidth, which would increase data-transfer rates by an order of magnitude. The higher-frequency signals proposed for 5G can’t travel through buildings like their lower-frequency 4G counterparts, but specialized antenna arrays would transmit the 5G signal across long distances. Earlier this year, two telecom companies in South Korea launched small 5G networks using busy lower-frequency bands, and Verizon deployed a 5G test in Chicago at the higher-frequency 28 GHz band.

Widespread 5G deployment will depend on building a new infrastructure of antennas that operate in high-frequency radio bands. Telecom companies and US regulators support 24 GHz for 5G networks because of its greater bandwidth and because the 1–6 GHz radio spectrum is already crowded with 4G, digital TV, radar, and other applications. (The 24 GHz band spans 24.25–24.45 GHz and 24.75–25.25 GHz.)

Fifth-generation broadband wireless threatens weather forecasting
Alex Lopatka, Physics Today

LMADIS...

Topics: Applied Physics, Electromagnetic Radiation, Politics, Robotics

I normally cheer the usage and applications of recent technology. In light of recent events, this may not be a swift idea. The second through fourth letters of the acronym are quite (and maybe intentionally) ominous.

"War is the continuation of politics by other means." Carl von Clausewitz

*****

In June, Iran’s military shot down one of the U.S. Navy’s $130 million Global Hawk drones, claiming it had veered out of international airspace and into the nation’s territory.

Now, the U.S. Navy has returned the favor, using a new directed-energy weapon to disable an Iranian drone in the same region — marking the next-generation device’s first known “kill.”

According to a Department of Defense statement, a fixed wing drone approached the USS Boxer while the ship traveled through the Strait of Hormuz on July 18. The drone then came within a threatening range, prompting the crew to take “defensive action.”

A defense official later told Military.com on the condition of anonymity that the Navy took out the drone using its Light Marine Air Defense Integrated System (LMADIS), a new device that uses radio frequencies to jam drones.

Iran’s Minister of Foreign Affairs Mohammad Javad Zarif, meanwhile, has denied the incident altogether, telling reporters the nation has “no information about losing a drone.”

US Navy's Weapon Gets First "Kill," Shoots Down Iranian Drone
Kristin Houser, Futurism

Nano Zappers...

Topics: Biology, Cancer, Electromagnetic Radiation, Green Energy, Nanotechnology, Research

One potentially valuable way to attack cancer cells is to zap them with low-intensity alternating current. This interferes with the flow of calcium and potassium ions in and out of the cells, a process so important that disrupting it ultimately kills them.

But there is a problem with this approach: healthy cells are just as susceptible to ion channel disruption as cancer cells, so the treatment kills healthy and cancerous cells alike. What’s needed is a way to focus the treatment on cancer cells while leaving the healthy ones untouched.

Enter Attilio Marino at the Istituto Italiano di Tecnologia, Enrico Almici at the Polytechnic University of Turin, and colleagues in Italy. These guys use piezoelectric nanoparticles that generate current inside the body when repeatedly compressed with ultrasound. And they have gathered the first evidence that this could be turned into an effective treatment for cancer.

The technique is straightforward in theory. Piezoelectric materials generate a charge when squeezed (and similarly change shape when zapped with a voltage). They are widely used in everything from microphones to motors.

Marino and co’s idea is to inject biocompatible nanoparticles into the body and then bombard them with ultrasound. The high and low pressures associated with the ultrasound should cause the nanoparticles to generate a charge that interferes with ion channels and kills the cells. The team choose barium titanate nanoparticles, which are considered biocompatible since they contain no lead.

Electric nanoparticles can target and kill cancer cells by zapping them
Emerging Technology, arXiv

BOCs @ Home...

Quantum games: Artist’s impression of the Alice Challenge experimental setup. (Courtesy: ScienceAtHome/Aarhus University)

Topics: Bose-Einstein Condensate, Electromagnetic Radiation, Quantum Mechanics, Theoretical Physics

Citizen scientists have outperformed physicists in creating Bose–Einstein condensates (BECs) of ultracold atoms. That is the finding of an international team of scientists and social scientists, which ran the first-ever optimization challenge in which the public was able to create a BEC remotely by manipulating laser beams and magnetic fields. Optimization experts using state-of-the-art algorithms took a similar challenge and both groups created BECs containing more atoms than the physicists who had built the experiment – even though the physicists had months to perfect their techniques.

By studying the behavior of the 600 citizen scientists who participated, the team has uncovered insights into what makes human problem solving unique. As well as providing hints for creating advanced algorithms based on human intuition, the study suggests how to exploit the best of human and artificial intelligence in the future.

The research was done by Jacob Sherson and colleagues at Aarhus University in Denmark, Ulm University in Germany and the University of Sussex in the UK. Sherson and some of his colleagues have been involved in the ScienceAtHome project, which develops games that use the brainpower of the general public to solve quantum science challenges. In 2016, they described how more than 10,000 players of one of these games – Quantum Moves –had efficiently optimized operations that could run a hypothetical quantum computer. “[With Quantum Moves], we documented that humans can contribute to solving complex challenges,” says Sherson. “With our current work we now take on the challenge of starting to answer how they contribute.”

Citizen scientists excel at creating Bose–Einstein condensates
Benjamin Skuse, Physics World