Ian Mulvany

April 20, 2023

In our time - superconductivity

#inourtime/notes #blog/draft #superconductivity #physics 

A few weeks ago I listened to the in our time episode on superconductivity. https://www.bbc.co.uk/programmes/m001hfpc  

It was a really enjoyable episode, though I can’t recall a lot from the episode, I did learn a few things. 

The phenomenon was discovered accidentally in 1911 by Kamerlingh Onnes https://en.wikipedia.org/wiki/Heike_Kamerlingh_Onnes, and it was a byproduct of creating liquid helium. 

Most of the history of the development of the filed has been the triumph of experiment over theory, and it is a real poster child for the importance of experimentation in our experimental philosophy. 

The episode delved into the mechanism behind the formation of Cooper pairs, which play a crucial role in superconductivity. In simple terms, a Cooper pair consists of two electrons that are somehow attracted to each other, despite their negative charge, enabling the superconducting state.

The formation of Cooper pairs is closely linked to low temperatures. As the temperature of a material drops, the lattice structure of its atoms vibrates less, allowing electrons to interact with the lattice in a unique way. When an electron moves through the lattice, it causes the positively charged atomic nuclei to be attracted towards it, creating a temporary region of higher positive charge. This positively charged region can then attract a second electron, causing the two electrons to become correlated, forming a Cooper pair.

The presence of many Cooper pairs within the material allows for a coordinated motion of electrons without resistance, resulting in the superconducting state. 

If you want to dig into in our time episodes more there is a fantastic site that allows you to explore the archive in all sorts of ways:  https://genmon.github.io/braggoscope/

About Ian Mulvany

Hi, I'm Ian - I work on academic publishing systems. You can find out more about me at mulvany.net. I'm always interested in engaging with folk on these topics, if you have made your way here don't hesitate to reach out if there is anything you want to share, discuss, or ask for help with!