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Quantum light source could pave the way to a quantum internet

The ability to integrate fiber-based quantum information technology into existing optical networks would be a significant step toward applications in quantum communication. To achieve this, quantum light sources must be able to emit single photons with controllable positioning and polarization and at 1.35 and 1.55 micrometer ranges where light travels at minimum loss in existing optical fiber networks, such as telecommunications networks. This combination of features has been elusive until now, despite two decades of research efforts.

Recently, two-dimensional (2D) semiconductors have emerged as a novel platform for next-generation photonics and electronics applications. Although scientists have demonstrated 2D quantum emitters operating at the visible regime, single-photon emission in the most desirable telecom bands has never been achieved in 2D systems.

To solve this problem, researchers at Los Alamos National Laboratory developed a strain engineering protocol to deterministically create two-dimensional quantum light emitters with operating wavelength tunable across O and C telecommunication bands. The polarization of the emissions can be tuned with a magnetic field by harnessing the valley degree of freedom.

A “Quantum Brain” Could Solve The Hard Problem of Consciousness, New Research Suggests

One of the most enduring human mysteries is why we possess sentient awareness, a paradox known to science as the “hard problem of consciousness.”

At the physiological level, we have a good understanding that consciousness is driven by electrical impulses and chemical signals between neurons in the brain. Though precisely what regions of the brain are responsible for thoughtful experience is still a matter of debate.

However, scientists still do not understand why the same essential elements of the universe can come together to form an inanimate object like a rock or a highly complex organic structure like the human brain.

A room-temperature terahertz camera based on a CMOS and quantum dots

Terahertz (THz) radiation is electromagnetic radiation ranging from frequencies of 0.1 THz to 10 THz, with wavelengths between 30μm and 3mm. Reliably detecting this radiation could have numerous valuable applications in security, product inspection, and quality control.

For instance, THz detectors could allow law enforcement agents to uncover potential weapons on humans or in luggage more reliably. It could also be used to monitor without damaging them or to assess the quality of food, cosmetics and other products.

Recent studies introduced several devices and solutions for detecting terahertz radiation. While a few of them achieved promising results, their performance in terms of sensitivity, speed, bandwidth and operating temperature is often limited. Researchers at Massachusetts Institute of Technology (MIT), University of Minnesota, and other institutes in the United States and South Korea recently developed a that can reliably detect THz radiation at room temperature, while also characterizing its so-called polarization states. This camera, introduced in a paper published in Nature Nanotechnology, is based on widely available complementary metal-oxide-semiconductors (CMOS), enhanced using (i.e., nm-sized semiconductor particles with advantageous optoelectronic properties).

In a world first, physicists move light back and forth in time simultaneously

The experiment could help to form a unified theory of quantum gravity.

Scientists have, for the first time ever, made light appear to move simultaneously forward and backward in time. The new method, achieved by an international group of scientists, could help create novel quantum computing techniques and give scientists a better understanding of quantum gravity, a report from LiveScience.

It was achieved thanks to a combination of two principles that form a part of the bizarre world of quantum mechanics.

What is a “quantum time flip”?


NeoLeo/iStock.

The new method, achieved by an international group of scientists, could help create novel quantum computing techniques and give scientists a better understanding of quantum gravity, a report from LiveScience reveals.