Quantum-mechanical monopoles discovered

We did it! Our monopole collaboration (Aalto University, Finland, and Amherst College, USA) succeeded in observing an isolated point-like monopole in a quantum field itself for the first time. This discovery connects to important characteristics of the elusive magnetic monopole. The results will be published tomorrow in Science magazine.


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

We performed an experiment in which we modified a gas of rubidium atoms prepared in a nonmagnetic state, so-called polar phase, near absolute zero temperature. Under these extreme conditions we were able to create a monopole in the quantum-mechanical field that describes the gas. This structure, know as a topological point defect, resembles, for example, that of the magnetic monopole particle as described in grand unified theories of particle physics.


 Comparison of the experimentally obtained image of the Bose–Einstein condensate containing the monopole (left) with the theoretical prediction (right). Brighter area has higher particle density and the different colors denote the internal spin state of the atoms. Credit: monopole collaboration.

In an experiment published about a year ago, we used the gas to detect a monopole within a synthetic (a.k.a. artificial) magnetic field, but there was no isolated monopole in the quantum field describing the gas itself. Now we have finally witnessed the quantum-mechanical monopole!

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

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View towards the main experimental chamber of the apparatus at Amherst College, showing the magnetic field coils and optical components required to create the superfluid containing the isolated monopole. Credit: Marcus DeMaio/Amherst College April 2015.

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

The discovery of a magnetic monopole particle is still in the future. However, our 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.

And now enjoy our video telling how the monopoles were created and modelled:

Finally, I give thumbs up for the hard-working scientists at Large Hadron Collider (LHC) and IceCube Neutrino Observatory. They are looking for the magnetic monopole particle! I hope that they succeed.


Original article (available from May 1st, 2015):

M. W. Ray, E. Ruokokoski, K. Tiurev, M. Möttönen, and D. S. Hall, ”Observation of isolated monopoles in a quantum field”, Science, DOI: 10.1126/science.1258289 (2015).

Previous work:

M. W. Ray, E. Ruokokoski, S. Kandell, M. Möttönen, and D. S. Hall, “Observation of Dirac Monopoles in a Synthetic Magnetic Field”, Nature 505, 657 (2014).

Posted by Mikko

About Mikko

Mikko is the leader of Quantum Computing and Devices (QCD) Labs at Aalto University, Department of Applied Physics. His main research interests include quantum nanoelectronics and quantum gases.
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One Response to Quantum-mechanical monopoles discovered

  1. Serge Perreault says:

    Thank you !

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