Category Physics

Making a ‘Sandwich’ out of Magnets and Topological Insulators, Potential for Lossless Electronics

When two ferromagnets are placed on the top and bottom surfaces of a topological insulator, a gap is opened in the topological surface state, whilst the edge allows electrons to flow without resistance.

A Monash University-led research team has discovered that a structure comprising an ultra-thin topological insulator sandwiched between two 2D ferromagnetic insulators becomes a large-bandgap quantum anomalous Hall insulator.

Such a heterostructure provides an avenue towards viable ultralow energy future electronics, or even topological photovoltaics.

Topological Insulator: The Filling in the Sandwich

In the researchers’ new heterostructure, a ferromagnetic material forms the ‘bread’ of the sandwich, while a topological insulator (ie, a material displaying nontrivial topology) ...

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The future of 5G+ Infrastructure could be built Tile by Tile

Two fabricated proof-of-concept tile arrays are shown alongside two inkjet-printed tile arrays, which the team will present on at the upcoming International Microwave Symposium in June. Credit: Georgia Tech

5G+ (5G/Beyond 5G) is the fastest-growing segment and the only significant opportunity for investment growth in the wireless network infrastructure market, according to the latest forecast by Gartner, Inc. But currently 5G+ technologies rely on large antenna arrays that are typically bulky and come only in very limited sizes, making them difficult to transport and expensive to customize.

Researchers from Georgia Tech’s College of Engineering have developed a novel and flexible solution to address the problem...

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Quantum Physics sets a Speed Limit to Electronics

An ultra short laser pulse (blue) creates free charge carriers, another pulse (red) accelerates them in opposite directions.

Semiconductor electronics is getting faster and faster — but at some point, physics no longer permits any increase. The speed can definitely not be increased beyond one petahertz (one million gigahertz), even if the material is excited in an optimal way with laser pulses.

How fast can electronics be? When computer chips work with ever shorter signals and time intervals, at some point they come up against physical limits. The quantum-mechanical processes that enable the generation of electric current in a semiconductor material take a certain amount of time. This puts a limit to the speed of signal generation and signal transmission.

TU Wien (Vienna), TU Gra...

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Physicists Create Extremely Compressible ‘Gas of Light’ – Paving the way to new types of highly sensitive sensors

The centerpiece of the experiment: – the optical microresonator realizes the ‘photon box’.
Photo: Volker Lannert/University of Bonn

Researchers at the University of Bonn have created a gas of light particles that can be extremely compressed. Their results confirm the predictions of central theories of quantum physics. The findings could also point the way to new types of sensors that can measure minute forces. The study is published in the journal Science.

If you plug the outlet of an air pump with your finger, you can still push its piston down. The reason: Gases are fairly easy to compress — unlike liquids, for example. If the pump contained water instead of air, it would be essentially impossible to move the piston, even with the greatest effort.

Gases usually consist of at...

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