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Haldane Model: Does edge current exist for a filled band?

  1. Dec 2, 2015 #1
    Hi all,

    I'm currently trying to investigate the edge current on a finite strip of Zigzag Haldane model (spinless, pi/2 phase) and I measure the current (in my code) by taking the expectation value of my current operator which is a function of wavevector k, for each eigenvector of the wavevector-dependent Hamiltonian H(k). The current operator is the net directional hopping matrix when considering only a line across the sample.

    When I set the fermi level at the point of the top of the edge mode band, I get zero net current, for a quantum hall system, should this not be a non-zero current? Im confused

  2. jcsd
  3. Dec 7, 2015 #2
    Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
  4. Dec 7, 2015 #3
    Hello. Can you write down this current operator you speak of?

    What exactly do you mean by 'the point of the top of the edge mode band'?

    I suppose in general I am confused about a few things: since you talk about k it seems you are doing periodic boundary conditions, but since you mention edge mode band it sounds like you are doing open boundary conditions?
    Also, do we expect a current if there is no applied electric field?
    Both of these questions might have to do with me not knowing what the current operator is you are using?
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