System Bits: Aug. 11

Fundamental physics discovery
The study of correlated electrons — a branch of fundamental physics research — focuses on interactions between the electrons in metals, which now are understood a bit better, according to Caltech researchers.

Understanding these interactions and the unique properties they produce could lead to the development of novel materials and technologies, but they must be experimentally verified and the interactions at microscopic scales physically probed.

As such, Caltech’s Thomas F. Rosenbaum and colleagues at the University of Chicago and the Argonne National Laboratory used a synchrotron X-ray source to investigate the existence of instabilities in the arrangement of the electrons in metals as a function of both temperature and pressure, and to pinpoint, for the first time, how those instabilities arise.

This cutaway schematic shows the diamond anvil cell, a pressure vessel in which the experiments were conducted. The target material is situated between two diamonds, represented here in blue. For this study, a diamond anvil generated pressures to 100,000 times sea level.
(Source: University of Chicago/Argonne National Laboratory)

They spent over 10 years developing the instrumentation to perform these studies, and they now have a very unique capability that’s due to the long-term relationship between Dr. Rosenbaum and the facilities at the Argonne National Laboratory, the researchers said.

A better virtual reality headset
Try on any virtual reality headset and within a few minutes the sense of wonder might wear off and leave you with a headache or a topsy-turvy stomach. But now, a light-field stereoscope that creates a dramatically more natural virtual reality experience than what is present in today’s leading headsets has been created by assistant professor Gordon Wetzstein’s Computational Imaging Group at Stanford University.

Fu-Chung Huang demonstrates the new light-field stereoscope virtual reality headset in the Stanford Computational Imaging Group lab. (Source: Stanford University)

According to computational imaging experts, the reason the user of a virtual reality headset may experience a headache or motion sickness is because current virtual reality headsets don’t simulate natural 3D images.

The prototype virtual reality headset from the Stanford Computational Imaging Group uses light-field technology to create a natural, comfortable 3D viewing experience.

The researchers explained that in current “flat” stereoscopic virtual reality headsets, each eye sees only one image. Depth of field is also limited, as the eye is forced to focus on only a single plane. In the real world, we see slightly different perspectives of the same 3D scene at different positions of our eye’s pupil, and we constantly focus on different depths. When someone looks through a low-cost cardboard virtual reality headset or even a more expensive headset, there is a conflict between the visual cues the eyes focus on and how the brain combines what the two eyes see, called “vergence.”

The new light-field stereoscope technology solves that disconnect by creating a sort of hologram for each eye to make the experience more natural. A light field creates multiple, slightly different perspectives over different parts of the same pupil. The result: the user can freely move their focus and experience depth in the virtual scene, just as in real life.

Making non-magnetic metals magnetic
University of Leeds researchers have demonstrated for the first time how to generate magnetism in metals that are not naturally magnetic, which could end our reliance on some rare and toxic elements currently used.

Scientists there have detailed a way of altering the quantum interactions of matter in order to “fiddle the numbers” in a mathematical equation that determines whether elements are magnetic, called the Stoner Criterion.

Fatma Al Ma’Mari, from the School of Physics & Astronomy at the University of Leeds said being able to generate magnetism in materials that are not naturally magnetic opens new paths to devices that use abundant and hazardless elements, such as carbon and copper. This is significant because magnets are used in many industrial and technological applications, including power generation in wind turbines, memory storage in hard disks and in medical imaging.

(Source: University of Leeds)

Of course future technologies, such as quantum computers, will require a new breed of magnets with additional properties to increase storage and processing capabilities but the researchers believe this is a step towards creating such ‘magnetic metamaterials’ that can fulfill this need.