Lifeboat Foundation

When you shine a beam of light on your hand, you don’t feel much, except for a little bit of heat generated by the beam. When you shine that same light into a world that is measured on the nano- or micro scale, the light becomes a powerful manipulating tool that you can use to move objects around – trapped securely in the light.

Electrical engineers in the accelerator physics group at TU Darmstadt have developed a design for a laser-driven electron accelerator so small it could be produced on a silicon chip. It would be inexpensive and with multiple applications. The design, which has been published in Physical Review Letters, is now being realised as part of an international collaboration.

IMAGE: The driving laser field (red) ‘shakes’ electrons in graphene at ultrashort time scales, shown as violet and blue waves. A second laser pulse (green) can control this wave and thus determine the direction of current. (Image credit: FAU/Christian Heide)

Being able to control electronic systems using light waves instead of voltage signals is the dream of physicists all over the world. The advantage is that electromagnetic light waves oscillate at petaherz frequency. This means that computers in the future could operate at speeds a million times faster than those of today. Scientists at Friedrich-Alexander University (FAU; Erlangen-Nurenberg, Germany) have now come one step closer to achieving this goal as they have succeeded in using ultra-short laser impulses to precisely control electrons in graphene. The scientists published their results in Physical Review Letters.

Current control in electronics that is one million times faster than in today’s systems is a dream for many. Ultimately, current control is one of the most important components as it is responsible for data and signal transmission. Controlling the flow of electrons using light waves instead of voltage signals, as is now the case, could make this dream a reality. However, up to now, it has been difficult to control the flow of electrons in metals as metals reflect light waves and the electrons inside them cannot be influenced by these light waves.

Continue reading “Ultrafast laser pulses control electrons in graphene, making ultrafast computing possible” »

For the research, scientists had to work with single protons.

Physicist Wang Yifang, the mastermind behind the project, gives Nature an update on plans for an ambitious facility.

Every action creates an equal and opposite reaction. It’s perhaps the best known law of physics, and Guido Fetta thinks he’s found a way around it.

According to classical physics, in order for something—like a spaceship—to move, conservation of momentum requires that it has to exert a force on something else. A person in roller skates, for example, pushes off against a wall; a rocket accelerates upward by propelling high-velocity combusted fuel downward. In practice, this means that space vessels like satellites and space stations have to carry up to half their weight in propellant just to stay in orbit. That bulks up their cost and reduces their useful lifetime.

Melting gold normally requires temperatures upwards of 1,064° C (1,947° F), but physics is never quite that simple. A team of researchers has now found a way to melt gold at room temperature using an electric field and an electron microscope.

A team of researchers from the Earthquake Research Institute, Department of Civil Engineering and Information Technology Center at the University of Tokyo, and the RIKEN Center for Computational Science and RIKEN Center for Advanced Intelligence Project in Japan were finalists for the coveted Gordon Bell Prize for outstanding achievements in high-performance computing. Tsuyoshi Ichimura together with Kohei Fujita, Takuma Yamaguchi, Kengo Nakajima, Muneo Hori and Lalith Maddegedara were praised for their simulation of earthquake physics in complex urban environments.

Scientists used to think a “warp bubble” would require an impractical amount of energy. That’s starting to change.