Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers watch quantum knots untie

23.10.2019

After first reporting the existence of quantum knots, Aalto University & Amherst College researchers now report how the knots behave

A quantum gas can be tied into knots using magnetic fields. Our researchers were the first to produce these knots as part of a collaboration between Aalto University and Amherst College, USA, and they have now studied how the knots behave over time.


Particle densities related to the decay of the quantum knot (left), which surprised researchers by untying itself after a few microseconds and eventually turning into the spin vortex, (right)

Image credit: Tuomas Ollikainen/Aalto University


The experimental set-up at Amherst College where quantum gasses are made

Credit: David Hall/Amherst College

The surprising result is that the knots untie themselves over a short period of time, before turning into a vortex.

The research was mainly carried out by Tuomas Ollikainen, a PhD student at Aalto university who split his time between carrying out experimental work in Amherst in Massachusetts, and analyzing the data and developing his theories at Aalto.

"We hadn't been able to study the dynamics of these sorts of three-dimensional structures experimentally before, so this is the first step to this direction." says Ollikainen.

"The fact that the knot decays is surprising, since topological structures like quantum knots are typically exceptionally stable. It's also exciting for the field because our observation that a three-dimensional quantum defect decays into a one-dimensional defect hasn't been seen before in these quantum gas systems"

The researchers hope their new study opens up new avenues in experimental research. One of the key breakthroughs in the study was being able to have better control over the state of the quantum gas, which allowed them to detect changes in its structure, like the decay of the knots and the formation of the vortex.

"Of course one can simulate these things but actually making quantum knots is not that easy. By being able to control the environment better we can explore different effects and get to understand more about these exciting quantum systems." tells Ollikainen.

"When we tied quantum knots in 2016, it was the first realization of three-dimensionally winding topological structures. That was like breathing air another planet for the first time. Amazing." says Prof. Mikko Möttönen, head of Quantum Computing and Devices group where Ollikainen works.

"I know that many researchers have paid attention to our work and got inspiration to try this out in completely different type of systems. It would be great to see this technology being used some day in a practical application, which may well happen. Our latest results show that while quantum knots in atomic gases are exciting, you need to be quick to use them before they untie themselves. Thus the first applications are likely to be found in other systems." Möttönen continues.

###

The Quantum Computing and Devices group is a part of QTF, the Academy of Finland Centre of Excellence for Quantum Technology. The research benefitted from the computational resources from CSC-IT Center for Science Ltd. and Aalto Science-IT project.

Media Contact

Tuomas Ollikainen
tuomas.ollikainen@aalto.fi
358-504-354-066

 @aaltouniversity

http://www.aalto.fi/en/ 

Tuomas Ollikainen | EurekAlert!
Further information:
https://www.aalto.fi/en/news/researchers-watch-quantum-knots-untie
http://dx.doi.org/10.1103/PhysRevLett.123.163003

More articles from Physics and Astronomy:

nachricht TU Graz researchers develop new 3D printing for the direct production of nanostructures
13.11.2019 | Technische Universität Graz

nachricht A new approach to the hunt for dark matter
13.11.2019 | Johannes Gutenberg-Universität Mainz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New Pitt research finds carbon nanotubes show a love/hate relationship with water

Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.

New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...

Im Focus: Magnets for the second dimension

If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.

Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...

Im Focus: A new quantum data classification protocol brings us nearer to a future 'quantum internet'

The algorithm represents a first step in the automated learning of quantum information networks

Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...

Im Focus: Distorted Atoms

In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.

An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...

Im Focus: A Memory Effect at Single-Atom Level

An international research group has observed new quantum properties on an artificial giant atom and has now published its results in the high-ranking journal Nature Physics. The quantum system under investigation apparently has a memory - a new finding that could be used to build a quantum computer.

The research group, consisting of German, Swedish and Indian scientists, has investigated an artificial quantum system and found new properties.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

High entropy alloys for hot turbines and tireless metal-forming presses

05.11.2019 | Event News

Smart lasers open up new applications and are the “tool of choice” in digitalization

30.10.2019 | Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

 
Latest News

Magnetic tuning at the nanoscale

13.11.2019 | Physics and Astronomy

At future Mars landing spot, scientists spy mineral that could preserve signs of past life

13.11.2019 | Physics and Astronomy

Necessity is the mother of invention: Fraunhofer WKI tests utilization of low-value hardwood for wood fiberboard

13.11.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>