Physicists discover quantum-mechanical monopoles

Quantum-mechanical monopoles discovered
Artistic illustration of a quantum-mechanical monopole. Credit: Heikka Valja

Researchers at Aalto University (Finland) and Amherst College have observed a point-like monopole in a quantum field itself for the first time. This discovery connects to important characteristics of the elusive monopole magnet. The results were just published in Science magazine.

The researchers performed an experiment in which they manipulated a of rubidium atoms prepared in a nonmagnetic state near . Under these extreme conditions they were able to create a in the quantum-mechanical field that describes the gas.

'In this nonmagnetic state, a structure was created in the field describing the gas, resembling the particle as described in grand unified theories of particle physics. Previously, we have used the gas to detect a monopole within a so-called synthetic magnetic field, but there has been no monopole in the describing the gas itself. Now we have finally witnessed the quantum-mechanical monopole!', enthuses Dr. Mikko Möttönen, Aalto University.

'In the nonmagnetic state of the gas, no quantum whirlpools or monopoles are created in the synthetic magnetic field. However, quantum-mechanical magnetic order prevails in the sample, and we were able to manipulate this with adjustments to an externally applied magnetic field', Möttönen continues.

'The control of those magnetic fields must be stable to a small fraction of the size of the Earth's ', adds Prof. David Hall, Amherst College. 'The main experimental challenge we faced is to prepare the ultracold gas under highly sensitive conditions, in which field fluctuations due to the motion of metal objects or power line variations can make observation of the monopoles difficult.', Hall continues.

The result is a remarkable step forward in quantum research. It is important to understand the structure of monopoles and other topological entities, in part because they appear in the models describing the early universe and affect the properties of many different materials, such as metals.

Credit: Aalto University

The discovery of a magnetic monopole particle is still in the future. This new result establishes that the structure of a quantum mechanical monopole does appear in nature, and therefore it further supports the possibility that magnetic monopoles exist.

Quantum-mechanical monopoles discovered
An image of an experimentally created Bose-Einstein condensate containing the monopole (left) and the corresponding theoretical prediction (right). Brighter area has higher particle density and the different colors denote the internal spin state of the atoms. The monopole is located in the center of the condensate. Credit: monopole collaboration

Explore further

Physicists create synthetic magnetic monopole predicted more than 80 years ago

More information: Observation of isolated monopoles in a quantum field, Science, www.sciencemag.org/lookup/doi/ … 1126/science.1258289
Journal information: Science

Provided by Aalto University
Citation: Physicists discover quantum-mechanical monopoles (2015, April 30) retrieved 18 November 2019 from https://phys.org/news/2015-04-physicists-quantum-mechanical-monopoles.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
1625 shares

Feedback to editors

User comments