# Is it possible to calculate Tsupercon from the unit cell?

• I
Hi folks,

It is an elementary question for people expert in superconductivity.

I know there is a theory, the BCS theory, and the GIzburg Landau theory too that apparently explains superconductivity.

My question is, if I give you a unit cell would you be able to tell me the temperature at which that solid enters into the superconducting state?

And the same question for high temperature superconductors, Is there a theory that tells you the Tc if the unit cell is known?

f95toli
Gold Member
For BCS (conventional) superconductor it is possible to calculate Tc if you know the structure (which we nearly always do, we are very, very good at determining crystal structures). However, you need advanced computer simulations to do so, it can't be done analytically.

High temperature superconductor are very different. We do not even fully understand why these materials are superconducting, meaning there are no models that can be used to predict Tc.

jonjacson
For BCS (conventional) superconductor it is possible to calculate Tc if you know the structure (which we nearly always do, we are very, very good at determining crystal structures). However, you need advanced computer simulations to do so, it can't be done analytically.

High temperature superconductor are very different. We do not even fully understand why these materials are superconducting, meaning there are no models that can be used to predict Tc.

Thanks!

So scientists are able to synthesize them but without the underlying theory, interesting.

f95toli
Gold Member
Thanks!

So scientists are able to synthesize them but without the underlying theory, interesting.

We do have SOME ideas about what makes them superconducting (e.g. the role of the CuO2 in the cuprates) so it is not like the chemists are just combining elements at random, if you look at the structure of say the cuprates you will find that they have a similar structure so that is a clue.

But yes, it is very possible that there are many more superconducting compounds out there that we don't know of (see the fairly recent discovery of the pnictides)

jonjacson
Look into:
The Eliashberg-Migdal formalism (basically extended BCS theory), and also
Dynamical Mean Field Theory (Kotliar) which has successfully predicted a superconductor (if I recall correctly, it was high-temperature).

It's complicated stuff!

jonjacson
Thanks!

I will have a look.

I know, but it is very interesting.