Monday, May 28, 2012

Talk Slides - Dale














2 comments:

  1. Something I bugged you about during your presentation: the quantum critical point.
    You mentioned (which agrees with wikipedia) that the quantum critical point is a special class of continuous phase transition that takes place at the absolute zero of temperature, typically in a material where the phase transition temperature has been driven to zero by the application of a pressure, field or through doping.

    If a phase transition occurs at absolute zero, is there like a latent heat or something that is produced/taken when there is a phase transition?
    I suppose it might not be valid to think like that since it's a continuous phase transition?

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  2. To be truthful, I'm not 100% sure on that one.

    As I (breifly) mentioned, the paper justifies the process of quasiparticles breaking down due to the Wiedemann-Franz Law being violated in this phase transition region. Now this phase transition isn't so much like ice to water, where it's just the crystal structure of ice breaking down but the molecules stay the same, but rather the actual molecules change at this phase transition as the 4f quasi-hole becomes mobile.

    As a result, my guess would be that there wouldn't be a required input of energy in order to allow the phase transition to occur. Of course, this gets complicated further still by the fact that at that same continuous phase transition between the two fermi surfaces of the molecule at 0K, there's also a phase transition between displaying antiferromagnetism or not!

    Truthfully, that actually might be something they are still trying to determine. The experiment was run at finite temperature remember, and the results extrapolated down to 0K. And being a continuous phase transition over a range of B and T, I would say that there isn't a set value for an equivalent latent heat, or whatnot to allow the transition to take place.

    Just my rambling thoughts....

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