Researchers from Helmholtz-Zentrum Berlin (HZB) and the French research facility CNRS, south of Paris, are using electric fields to manipulate the property of electrons known as "spin" to store data permanently. This principle could not only improve random access memory in computers, it could also revolutionize the next generation of electronic devices.
This new kind of memory exploits a phenomenon called "tunnel magnetoresistance" or TMR. Two thin layers of a magnetic material are separated from each other by an insulator a mere millionth of a millimetre thick. Even though the insulator does not actually allow electrons to pass through it, some of the charge carriers still manage to sneak from one side to the other, as if by slipping through a tunnel. This is one of their quirky quantum behaviours. Another property it exploits is the intrinsic angular momentum of all electrons, which physicists call "spin". There are two spin states an electron can be in: either "up" or "down".
If most of the spins are oriented the same way in both magnetic layers of this TMR sandwich, then electrons tunnel much more easily than if one magnetic layer has mostly "up" spins and the other has mostly "down" spins. Such a component is used to build memory capable of rapid and repeated data writes, much like conventional memory, but also capable of permanently storing this data.
TMR-based memory known as MRAM has so far required relatively strong magnetic fields to write data, and therefore a lot of energy. As CNRS researchers Vincent Garcia and Manuel Bibes show in their work presented in journal Science, however, this could change. They made their insulator out of the compound barium titanate. HZB researchers Sergio Valencia and Florian Kronast used X-ray absorption spectroscopy (XAS) to study the chemical composition of the magnetic layers of this sandwich.
The scientists can use an electric field to switch the insulator in a way that influences the electron spins in the magnetic layers either side of it, thereby influencing the electron tunnelling as well. Since the insulator keeps the same switched state when all current is removed, this model could be used to build PC memory that draws very little power and still stores data permanently.
Articel in Science, DOI: 10.1126/science.1184028
Ferroelectric control of spin polarization: V. Garcia, M. Bibes, L. Bocher, S. Valencia, F. Kronast, A. Crassous, X. Moya, S. Enouz-Vedrenne, A. Gloter, D. Imhoff, C. Deranlot, N. D. Mathur, S. Fusil, K. Bouzehouane and A. Barthélémy
Dr. Sergio Valencia Molina | EurekAlert!
Construction of practical quantum computers radically simplified
05.12.2016 | University of Sussex
UT professor develops algorithm to improve online mapping of disaster areas
29.11.2016 | University of Tennessee at Knoxville
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
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,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Physics and Astronomy
08.12.2016 | Health and Medicine
08.12.2016 | Life Sciences