Category Physics

Researchers Unlock Light-Matter Interactions on Subnanometer Scales, Leading to ‘Picophotonics’

picophotonics in the 3D lattice of silicon atoms
The figure above demonstrates picophotonics in the 3D lattice of silicon atoms. The red wave represents the conventional electromagnetic wave propagating in the solid. The blue inner wave represents the new predicted picophotonic wave.  Graphic provided by Dr. Zubin Jacob.

Researchers at Purdue University have discovered new waves with picometer-scale spatial variations of electromagnetic fields that can propagate in semiconductors like silicon. The research team, led by Dr. Zubin Jacob, Elmore Associate Professor of Electrical and Computer Engineering and Department of Physics and Astronomy, published their findings in Physical Review Applied in a paper titled “Picophotonics: Anomalous Atomistic Waves in Silicon.”

“The word microscopic has its origins in the length scale of a micro...

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An On-Chip Time-Lens Generates Ultrafast Pulses

illustration of time lens
A time lens transforms a continuous-wave, single-color laser beam into a high-performance, on-chip femtosecond pulse source. (Credit: Second Bay Studios/Harvard SEAS)

Femtosecond pulsed lasers—which emit light in ultrafast bursts lasting a millionth of a billionth of a second—are powerful tools used in a range of applications from medicine and manufacturing, to sensing and precision measurements of space and time. Today, these lasers are typically expensive table-top systems, which limits their use in applications that have size and power consumption restrictions.

An on-chip femtosecond pulse source would unlock new applications in quantum and optical computing, astronomy, optical communications and beyond...

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Next Generation Material that Adapts to its History

Material that learns
The shape and conductivity of the pillars formed by magnetic beads in a magnetic field depend on the fields’ strength and history.

Responsive material changes its behavior based on earlier conditions
Inspired by living systems, researchers at Aalto University have developed a new material that changes its electrical behaviour based on previous experience, effectively giving it a basic form of adaptive memory. Such adaptive materials could play a vital role in the next generation of medical and environmental sensors, as well as in soft robots or active surfaces.

Responsive materials have become common in a range of applications, from glasses that darken in sunlight to drug delivery systems...

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Researcher Lauded for Superb Solution of Algorithmic Riddle from the 1950s

Road network with cars
Photo: Getty

Solving the riddle can reduce electric car battery consumption and make life tougher for currency speculators in the future. The discovery has just won the award for best research article and was honored at the field’s most prestigious conference in the United States.

For more than half a century, researchers around the world have been struggling with an algorithmic problem known as “the single source shortest path problem.” The problem is essentially about how to devise a mathematical recipe that best finds the shortest route between a node and all other nodes in a network, where there may be connections with negative weights.

Sound complicated? Possibly...

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