Nav: Home

A step towards probabilistic computing

May 14, 2019

When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are still lengths ahead of it: An example is signal processing, which plays an important role in autonomous driving. In the search for new computer concepts that are closer to the human brain, research is concentrating, amongst others, on probability-based computing. Together with his team, physicist Professor Ulrich Nowak from the University of Konstanz is investigating how these computers of the future can be made possible by using what are known as skyrmions, i.e. magnetic vortex-like configurations, as bit units. In collaboration with physicists from Johannes Gutenberg University Mainz, the researchers have now been able to show both in theory and experimentally how magnetic vortices can be used for new computing methods. The results were published in the current issue of the scientific journal Nature Nanotechnology.

In waking state, humans continually perceive everything going on around them. This perception generates data streams that the brain analyses on an ongoing basis. For example, if a sound becomes louder and louder, from a certain threshold upwards it might be identified as the danger of an object flying towards you. The brain does not react to specific numerical values but instead to signals that occur with certain probabilities. As with the quantum computer, it is hoped that the future generation of computers, which uses skyrmions to process and store data streams, will offer far higher storage capacity, speed and energy efficiency. Indeed, the stable magnetic skyrmions also have the advantage that they make computing with random signals conceivable.

The working group in Mainz led by Professor Mathias Kläui has succeeded in developing a material in which skyrmions can form. The researchers have also developed a method to exploit thermal diffusion of skyrmions in what is referred to as a reshuffler, a component needed for probabilistic computing. Ulrich Nowak's team was able to show in a simulation that the skyrmions observed indeed behaved like particles and moved around randomly in the plane, similarly to atoms that distribute themselves in gas or liquid at finite temperature.

This property is used for the reshuffler. "We have shown according to which laws diffusion occurs, its length and time scales and that it can be measured," said Ulrich Nowak, summarizing the Konstanz researchers' contribution to the joint project. Up until now, there have been no quantitative predictions for this. Only the combination of the measurements performed by Nowak's colleagues in Mainz and the simulations conducted in Konstanz has shown the relevance of skyrmion diffusion. Since skyrmions can be produced and rearranged by means of electric currents, they are suitable candidates for a reshuffler.

What is understood by a reshuffler is a component of probability-based computing that automatically scrambles input data like a kind of mixer. The reshuffler produces a sequence with the same number of memory units but in a different order. Their probability has therefore remained the same.
-end-
Key facts:

* Original publication: Jakub Zázvorka, Florian Jakobs, Daniel Heinze, Niklas Keil, Sascha Kromin, Samridh Jaiswal, Kai Litzius, Gerhard Jakob, Peter Virnau, Daniele Pinna, Karin Everschor-Sitte, Levente Rózsa, Andreas Donges, Ulrich Nowak & Mathias Kläui: Thermal skyrmion diffusion used in a reshuffler device. Nature Nanotechnology, 22 April 2019. DOI: https://doi.org/10.1038/s41565-019-0436-8

* Collaboration between the working groups led by Professor Ulrich Nowak at the University of Konstanz and his colleague Professor Mathias Kläui from Johannes Gutenberg University Mainz. Mathias Kläui worked at the University of Konstanz from 2003 to 2008, earning his habilitation (postdoctoral qualification) at the University of Konstanz in 2008.

* Combination of measurements from Mainz with simulations from Konstanz show the relevance of skrymion diffusion.

* The research work by the University of Konstanz was funded in the framework of the "Skyrmionics" Priority Programme of the German Research Foundation and Collaborative Research Centre (CRC) 767 of the University of Konstanz.

Note to editors:

You can download a photo here: https://cms.uni-konstanz.de/fileadmin/pi/fileserver/2019/Bilder/ein_schritt_skyrmionenmixer.jpg

Caption: The reshuffler works like a skyrmion mixer: A specific initial sequence is entered and the outcome is a randomly altered sequence of output states.

Copyright: Working group of Professor Ulrich Nowak, University of Konstanz

Film: Computer simulation of diffusive skyrmion motion in a thin magnetic film.

http://www.uni-konstanz.de/broschueren/video/ein_schritt_diffusionmovie.mov

Copyright: Working group of Professor Ulrich Nowak, University of Konstanz

Contact

University of Konstanz
Communications and Marketing
Phone: + 49 7531 88-3603
E-Mail: kum@uni-konstanz.de

University of Konstanz

Related Brain Articles:

Study describes changes to structural brain networks after radiotherapy for brain tumors
Researchers compared the thickness of brain cortex in patients with brain tumors before and after radiation therapy was applied and found significant dose-dependent changes in the structural properties of cortical neural networks, at both the local and global level.
Blue Brain team discovers a multi-dimensional universe in brain networks
Using a sophisticated type of mathematics in a way that it has never been used before in neuroscience, a team from the Blue Brain Project has uncovered a universe of multi-dimensional geometrical structures and spaces within the networks of the brain.
New brain mapping tool produces higher resolution data during brain surgery
Researchers have developed a new device to map the brain during surgery and distinguish between healthy and diseased tissues.
Newborn baby brain scans will help scientists track brain development
Scientists have today published ground-breaking scans of newborn babies' brains which researchers from all over the world can download and use to study how the human brain develops.
New test may quickly identify mild traumatic brain injury with underlying brain damage
A new test using peripheral vision reaction time could lead to earlier diagnosis and more effective treatment of mild traumatic brain injury, often referred to as a concussion.
This is your brain on God: Spiritual experiences activate brain reward circuits
Religious and spiritual experiences activate the brain reward circuits in much the same way as love, sex, gambling, drugs and music, report researchers at the University of Utah School of Medicine.
Brain scientists at TU Dresden examine brain networks during short-term task learning
'Practice makes perfect' is a common saying. We all have experienced that the initially effortful implementation of novel tasks is becoming rapidly easier and more fluent after only a few repetitions.
Balancing time & space in the brain: New model holds promise for predicting brain dynamics
A team of scientists has extended the balanced network model to provide deep and testable predictions linking brain circuits to brain activity.
New view of brain development: Striking differences between adult and newborn mouse brain
Spikes in neuronal activity in young mice do not spur corresponding boosts in blood flow -- a discovery that stands in stark contrast to the adult mouse brain.
Map of teenage brain provides evidence of link between antisocial behavior and brain development
The brains of teenagers with serious antisocial behavior problems differ significantly in structure to those of their peers, providing the clearest evidence to date that their behavior stems from changes in brain development in early life, according to new research led by the University of Cambridge and the University of Southampton, in collaboration with the University of Rome Tor Vergata in Italy.

Related Brain Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".