University of California scientists working at Los Alamos National Laboratory have developed a novel method for controlling and measuring electron spins in semiconductor crystals of GaAs (gallium arsenide). The work suggests an alternative--and perhaps even superior--method of spin manipulation for future generations of "semiconductor spintronic" devices.
In research published in todays issue of the scientific journal Physical Review Letters, Scott Crooker and Darryl Smith describe their use of a scanning optical microscope to acquire two-dimensional images of spin-polarized electrons flowing in semiconductor crystals mounted on an optical cryostat while using a miniature "cryogenic vise" to apply gentle pressure. By squeezing the crystal in a controlled manner, and without applying magnetic fields, the researchers were able to watch the electron spins rotate (or precess) as they flow through the crystal.
According to Crooker, "electrons, in addition to their negative electronic charge, also possess a magnetic "spin". That is, each electron behaves like a little bar magnet, with north and south poles. Electron spins in semiconductors are typically manipulated by applying a magnetic field, but weve found we can do the same thing, in a controlled fashion, using the "vise". And, the resulting degree of spatial spin coherence is remarkably more robust compared to the spin precession induced by a magnetic field."
Todd Hanson | EurekAlert!
Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT
Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
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