Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Trying to relate nuclear physics to solid state (fermi gas)

  1. May 2, 2015 #1
    In nuclear physics we have talked about the liquid drop model and the fermi gas model. My question is can a Fermi liquid and a Fermi gas be directly described using these models? Are they the same thing?

    i.e. If I wanted to decribe the difference between a fermi gas and a fermi liquid could I use the nuclear models to do this?
     
  2. jcsd
  3. May 2, 2015 #2

    ZapperZ

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    Well, why don't you use it and see if you come up with the same results? Start with comparing your models and see if you arrive at the same prediction as Landau's Fermi Liquid model.

    Zz.
     
  4. May 2, 2015 #3
    Thanks for the reply. To be honest (I should have put this in the original post) I'm trying to get more of a descriptive difference i.e.

    Can a fermi liquid be described (as in nuclear terms) as a drop of liquid being pulled by its surface tension into a spherical shape, thus as in a drop of liquid interactions occur but only with neighbours.

    And for the fermi gas, can the electrons (as in nuclear terms) be described as being able to move freely in a spherically symmetric potential well.

    I see what you are saying but we have been given for the fermi liquid model:

    IfGZN8K.jpg

    And for the fermi gas model, a calculation of fermi momentum and fermi energies.

    I wouldn't be sure how to relate the former to solid state.
     
  5. May 2, 2015 #4

    ZapperZ

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    I have a feeling we are using the same name but with different meanings.

    Whenever we refer to the "Fermi liquid" in condensed matter, we are specifically referring to the Landau's Fermi Liquid theory. This is essentially a renormalization of the electrons many-body problem into many one-body problem under a "weak-coupling" limit. A consequence of this is the concept of "quasiparticles", whereby the self-energies determine the coupling strength, lifetime, and other properties.

    From what I can see, I don't find any strong similarities in the nuclear models that you have mentioned.

    Zz.
     
  6. May 2, 2015 #5
    Ok, many thanks for that. I assumed they were the same and the simple difference between the fermi liquid and fermi gas could be described as interacting and non-interacting electrons respectively. I follow some of the description of the Fermi liquid you gave, it would really help if you could perhaps describe the difference of fermi liquid and fermi gas in solid state in layman's terms.
     
  7. May 2, 2015 #6

    ZapperZ

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    Oh, don't get me wrong, I'm not saying there isn't. I just haven't seen it yet. Someone who is more familiar with both of them might be able to chime in and correct me here.

    Many-body physics applies to both areas, because they should. How much one model resembles each other is something I am not so sure. That was why I asked if you can apply the nuclear models to the condensed matter scenario and get the same results as the Fermi liquid theory.

    Zz.
     
  8. May 2, 2015 #7
    Ok, I see, many thanks for your help!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Trying to relate nuclear physics to solid state (fermi gas)
Loading...