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Lecture | Tuesday Talks: Science Insights

Surprising vacuum forces in a superconductor

Tuesday 13 February 2024
Gorlaeus Building
Einsteinweg 55
2333 CC Leiden
Atrium, 1st floor

Surprising vacuum forces in a superconductor 

In this upcoming ‘Tuesday Talks: Science Insights’, we will dive into the realms of quantum mechanics and nanotechnology. A few months ago, Carlo Beenakker's interest was piqued by signs that Casimir's universal attractive force also manifests itself in superconductors. In his talk he will take you on the journey of his findings and how he conducted his research to get to the bottom of this.  

The force from nothing 
In 1948, Hendrik Casimir predicted a universal attractive force between two neutral metal plates at small distances. Universal, because the force is independent of the properties of the metals as long as they are good conductors. The attraction arises because the 19th-century concept of vacuum as empty space is wrong. Quantum mechanics tells us that vacuum is not empty at all but filled with particle-antiparticle pairs that emerge out of nothing and vanish back into nothing an instant later. In between the two plates these virtual particles have a lower density than outside. The resulting negative pressure pulls the plates together. 

Casimir meets Josephson
For many decades Casimir's ‘force from nothing’ was mainly of interest for fundamental physics. Recently it has become relevant for nanotechnology as well. Micro-electromechanical devices are small enough that their operation is influenced by the Casimir force. Superconducting nanostructures provide a way to control the force via the Josephson effect, which is the flow of current between two superconductors as a function of their phase difference. In this way the attractive force can be transformed into a repulsive force.

Join this edition of Tuesday Talks: Science Insights!

Everyone who is interested in this edition's topic is welcome. Please let us know if you are attending.

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About the speaker

Carlo Beenakker is a theoretical physicist at the Instituut-Lorentz of LION. He moved to Leiden University from the Philips Research Laboratories, where he learned about the vacuum force from Casimir himself. His current research, supported by an ERC Advanced grant, centres on topological quantum matter, as a platform for quantum computation.


The programme of the Tuesday Talks: Science Insights is:

15.45 hrs Take a seat
16.00 hrs Introduction by dean Jasper Knoester
16.10 hrs Lecture by speaker, followed by Q&A
17.00 hrs Drinks

About Tuesday Talks: Science Insights

Tuesday Talks: Science Insights is Leiden Science’s monthly dose of research inspiration from our staff, for our staff and all other curious minds. Every second Tuesday of the month from 16:00 hrs till 17:00 hrs, drinks and meet up afterwards till 18.00 hrs.

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