Question about electron vortexes in microscopes:

Originally posted by twhitehead
Thanks for the links. I don't think I understand it all, but I did learn something new.

The basic idea is: faster -> higher momentum -> smaller wavelength. Incidentally this is also why Bose-Einstein condensation generally requires low temperatures (this is the topic I am soon graduating on).

Originally posted by KazetNagorra
The basic idea is: faster -> higher momentum -> smaller wavelength. Incidentally this is also why Bose-Einstein condensation generally requires low temperatures (this is the topic I am soon graduating on).

Hey congrats! MS or PHD? What do you mean 'generally requires low temps'? You know it has to be in a realm of temperature just achieved in the last few years, microkelvin! One tenth of a kelvin would be like pouring molten iron in a jar of LN2!

Originally posted by sonhouse
Hey congrats! MS or PHD? What do you mean 'generally requires low temps'? You know it has to be in a realm of temperature just achieved in the last few years, microkelvin! One tenth of a kelvin would be like pouring molten iron in a jar of LN2!

MS.

The quantum degeneracy regime is easier to reach for high densities; for example superfluid helium-4 requires temperatures on the order of a few K, and superconductivity (which is also a form of BEC) has been demonstrated over 100K IIRC.

Originally posted by KazetNagorra
MS.

The quantum degeneracy regime is easier to reach for high densities; for example superfluid helium-4 requires temperatures on the order of a few K, and superconductivity (which is also a form of BEC) has been demonstrated over 100K IIRC.

I did not know superconductivity was a form of BEC or superfluidity in helium. Learn something new every day.

Any ideas what you will pursue for Phd?

BTW, my son in law went from undergrad to Phd in statistical physics, without EVER buying a book! That boggles my mind. It wasn't voluntary, he only had enough money for courses and room and board!

Originally posted by sonhouse
I did not know superconductivity was a form of BEC or superfluidity in helium. Learn something new every day.

Any ideas what you will pursue for Phd?

BTW, my son in law went from undergrad to Phd in statistical physics, without EVER buying a book! That boggles my mind. It wasn't voluntary, he only had enough money for courses and room and board!

In a superconducting system, you get pairs of electrons (which are fermions) which together form a composite boson (just like an atom can be a composite boson even though it consists purely of fermionic particles). These fermion pairs, called Cooper pairs, then Bose-Einstein condense into their ground state, which causes superconductivity (the superconductivity is related to the fact that the pairs cannot scatter off defects in the lattice of the conductor like normal electrons do - a pure, defect-free conductor actually also has zero resistance).

As for the PhD, nothing definitive yet.