Definitive Measurement of Spin-Triplet Superconductivity

I must be out of it, because I thought that there had already been a definitive measurement of such spin-triplet superconductivity before this. But based on this latest report, it appears that NMR measurement of such superconductivity has not been "definitive" until now.

To clarify, the Cooper pair states in most superconducting material are formed due to the pairing of electrons forming what is known as the singlet state. This is when the spin of one electron pairs with another electron that has an opposite direction of spin. Via Pauli Exclusion principle (or rules for fermions), these two electrons can be quite close to one another in space because they do not occupy the same spin states.

However, the physics also allows for the two electrons to pair up with their spins in the same direction. Unfortunately, again due to Pauli, because they have the same spin state, their spatial state cannot be the same, i.e. they can't be too close to one another. This is a more difficult way to sustain this pair. The reason why this is called the triplet state, as opposed to the single state of the more common pairing, is because quantum mechanics allows for three possible ways for these electrons to pair up (see figure below) when we make a measurement along a particular direction.

 

I think that this is a very good exercise to be included in an intro QM class because it is showing something very basic that could be used in such a class and it represents an application to a very important and advanced idea in condensed matter.

 

Zz. 

 

Imaging the Milky Way

If you missed it, I posted how I have gotten into astrophotography lately ever since I got a smart telescope earlier this year.

One of the things that I've always wanted to image is our Milky Way galaxy. Unfortunately, living in the suburbs of Chicago and with the light pollution (Bortle 9), it was almost impossible. I've been waiting for an opportunity to go elsewhere and attempt this. Well, that opportunity came last week when I got to spend a couple of week out in Hawaii (Kauai and Oahu, which BTW have been constantly on my mind the past couple of days due to Hurricane Lala). I brought the telescope with me with the intention of trying to see if I can do something. Didn't get clearly skies in Kauai, and didn't have clear skies in Oahu either until 3 days before we left.

On the beaches of Ko Olina in Oahu, we managed to finally capture the image of the center of the Milky Way using our Dwarf Mini telescope:

It turned out better than I expected. It took about half an hour of stacking to get this image. I wish we had more time to be able to do a mosaic because I wanted to try an image above and below the enter, but the clouds were already moving in. Still, we were pleased that we managed to accomplish our main goal.

And yes, you can bet that I'll be showing this in my astronomy class this Fall! 😊

Zz.