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Gizmorama - November 16, 2016

Good Morning,


You know what's super cool? Super-cooled electrons are super cool. Especially when they reveal their quantum nature. Sounds cool, right?

Learn about this and more interesting stories from the scientific community in today's issue.

Until Next Time,
Erin


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*-- Super-cooled electrons reveal their quantum nature --*

STUTTGART, Germany - When scientists cooled their scanning tunnelling microscope to temperatures approaching absolute zero, they discovered electrons moving at a snail's pace. Electric current failed to flow. Instead, it trickled.

At these extreme temperatures, scientists found, electrons reveal their quantum state. A quantum state is the understanding of a single entity within an isolated quantum system. In this instance, it is the understanding or approximation of an individual electron.

A scanning tunnelling microscope works by allowing a narrow electric current to flow across its tip onto the surface under examination. Perturbations in the flow allow scientists to glean information about the atomic structures found on the surface of the studied object or material.

But even at extremely low temperatures, the flow is still too fast to observe the movement of individual electrons. That is until the temperature approaches fifteen thousandth of a degree above absolute zero, or negative 273.135 degrees Celsius. At that point, electrons begin to trickle one by one like grains of sand falling through an hourglass.

The phenomenon yields new anomalies in the electric feedback recorded by the microscope -- new structures.

"We could explain these new structures only by assuming that the tunnelling current is a granular medium and no longer homogeneous," Christian Ast, a scientist at the Max Planck Institute for Solid State Research, said in a news release.

Researchers described their quantum experiments in a new paper, published this week in the journal Nature Communications. Their findings confirm theoretical hypothesis offered by scientist some two decades ago.

"The theory on which this is based was developed back at the beginning of the 1990s," said study co-author Joachim Ankerhold, a researcher from the University of Ulm. "Now that conceptual and practical issues relating to its application to scanning tunnelling microscopes have been solved, it is nice to see how consistently theory and experiment fit together."

It's not the first time electrons have revealed their quantum nature, but it is the first time a scanning tunneling microscope has been shown to have reached its quantum limit. Researchers are hopeful their findings will lead to new and unexpected quantum insights.

"These extremely low temperatures open up an unexpected richness of detail which allows us to understand superconductivity and light-matter interactions much better," concluded Ast.




*-- Melanin may boost strength of foams and fabrics --*

WASHINGTON - Creating stronger materials may be as simple as adding melanin, the molecule that lends skin its pigment and protects animals from ultraviolet rays.

In recent experiments, scientists found a small addition of melanin made polyurethane much stronger. Researchers described their findings in the journal Biomacromolecules.

Polyurethane mostly comes in the form of high-resistance foam, used most commonly for seating and insulation. But the material is used to enhance a variety of products, from epoxies to clothes.

Materials scientists have traded a range of additives and fillers in an attempt to bolster polyurethane, but gains have been modest and often isolated to singular physical qualities -- improving either tensile strength or toughness, but not both.

A material's tensile strength is its resistance to breaking under tension. Toughness describes a material's ability to absorb energy without breaking.

Experiments showed polyurethane samples containing just 2 percent melanin -- sourced from the ink sacs of cuttlefish -- were tougher and more resistant to tension than control materials.

***

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