#superfluid

It's tough to simulate nonlinear wave dynamics, so scientists often test theories in wave flumes, where they can create more controlled waves than what we see in the wild. But conventional wave flumes are big--meters-long, complicated equipment--and can only test a small range of conditions. To reach more extreme nonlinear dynamics, researchers have turned to a chip-based approach.  (Image and research credit: M. Reeves et al.; via Physics Today)

Quantum phase transition in indium oxide films defies superconductor norms

A team of physicists at Université Grenoble Alpes, CNRS, in France, working with a colleague from Karlsruhe Institute of Technology, in Germany, has observed an odd quantum phase transition in indium oxide films. In their study published in the journal Nature Physics, the group used microwave spectroscopy to study the internal properties and behavior of indium oxide films as they transitioned between superconducting and insulating states. Prior research has shown that when a superconductor undergoes a phase transition between superconductivity and insulation, its superfluid stiffness generally occurs in a smooth, continuous fashion. Superfluid stiffness is a measurement that has been developed to gauge how resistant a material is to changing from one phase to another. In this new study, the research team found an exception to that rule in indium oxide films. In their work, the researchers were investigating the properties of indium oxide, a material that, when chilled to a certain temperature, changes to a superconductor—it is also known to have multiple disorders at multiple levels. Such disorders give the material unusual properties.

#341 What is a superfluid?

I learned this today. A superfluid is a point where matter behaves like a fluid but has zero viscosity.A superfluid has no viscosity. That means it doesn’t have any friction and doesn’t lose energy. It appears to go against the laws of thermodynamics. If you stir a cup of coffee with a spoon and step away, the coffee will slowly stop spinning. If you stir a superfluid with a spoon and step away,…

Better late than never!

Here’s the last comic for Aquatic Space Month! 

Moving on to sparkly hot stars month now! :)

https://space.news/2019-02-28-universe-is-made-up-of-unknown-invisible-dark-fluid.html

https://www.dailymail.co.uk/sciencetech/article-2612949/Are-living-underwater-Researchers-believe-universe-liquid-superfluid.html

https://www.pbs.org/wgbh/nova/article/spacetime-might-superfluid-help-explain-gravity/

Superfluid Helium

It was previously thought that superfluid Helium would flow continuously without losing kinetic energy. Mathematicians at Newcastle University demonstrated that this is only the case on a surface completely smooth down to the scale of nanometers; and no surface is that smooth.

When a regular fluid like water is passing over a surface, friction creates a boundary layer that ‘sticks’ to surfaces. Just like a regular fluid, when superfluid Helium passes over a rough surface there is a boundary layer created. However the cause is very different. As superfluid Helium flows past a rough surface, mini tornados are created which tangle up and stick together creating a slow-moving boundary layer between the free-moving fluid and the surface. This lack of viscosity is one of the key features that define what a superfluid is and now we know why it still loses kinetic energy when passing over a rough surface.