Category Physics

When the screens are inserted into the beam, the desired patterns emerge: a cross or the logo of TU Wien.
Credit: TU Wien

Researchers succeed in shaping terahertz beams with extremely high precision. Terahertz radiation can be used for a wide variety of applications and is used today for airport security checks just as much as it is for material analysis in the lab. The wavelength of this radiation is in the millimetre range, meaning that it is significantly larger than the wavelength of visible light. It also requires specialised techniques to manipulate the beams and get them into the right shape...

New solid-state silicon device may one day power space missions. Researchers have developed a tiny silicon-based device that can harness what was previously called waste heat and turn it into DC power. Directly converting electrical power to heat is easy. It regularly happens in your toaster, that is, if you make toast regularly. The opposite, converting heat into electrical power, isn’t so easy.

“We have developed a new method for essentially recovering energy from waste heat. Car engines produce a lot of heat and that heat is just waste, right? So imagine if you could convert that engine heat into electrical power for a hybrid car. This is the first step in that direction, but much more work needs to be done,” said Paul Davids, a physicist and the principal investigator for the study...

Researchers demonstrate the first single-photon transistor using a semiconductor chip. They used a single photon, stored in a quantum memory, to toggle the state of other photons. Credit: E. Edwards/Joint Quantum Institute

Researchers have demonstrated the first single-photon transistor using a semiconductor chip. Transistors are tiny switches that form the bedrock of modern computing; billions of them route electrical signals around inside a smartphone, for instance. Quantum computers will need analogous hardware to manipulate quantum information. But the design constraints for this new technology are stringent, and today’s most advanced processors can’t be repurposed as quantum devices. That’s because qubits, have to follow different rules laid out by quantum physics.

Scientists can use ...

At left, different patterns of slices through a thin metal foil, are made by a focused ion beam. These patterns cause the metal to fold up into predetermined shapes, which can be used for such purposes as modifying a beam of light.
Credit: Courtesy of the researchers

Folding and cutting thin metal films could enable microchip-based 3D optical devices. Nanokirigami has taken off as a field of research in the last few years; the approach is based on the ancient arts of origami (making 3D shapes by folding paper) and kirigami (which allows cutting as well as folding) but applied to flat materials at the nanoscale, measured in billionths of a meter.

Now, researchers at MIT and in China have for the first time applied this approach to the creation of nanodevices to manipulate light, potentially...