Recent content by iamquantized

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    Graduate What is the effective mass of electrons in graphene?

    T. Ando had a paper on graphene. He performed a k.p expansion about the Dirac point and arrived at an equation which has the exact form as the Dirac equation. A more theoretical treatment would be this paper "Condensed-Matter Simulation of a Three-Dimensional Anomaly" by GW Semenoff -...
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    Graduate Can You Generate Feynman Diagrams for Specific Perturbation Orders?

    is there any program that can generate the feynman diagram for a specific perturbation of n-order contributions to Green function?
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    Graduate Weak localiztion and anti-localization

    Can someone explain to me briefly what is weak localiztion and anti-localization and its effect on magnetotransport? Thank you.
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    Graduate Visualize what chirality physically means

    Yes. I read it. thanks. Just that I cannot find resources that specifically relates chirality to solid state system and describing their interactions and relations to Dirac's equation... stuff of these sort.
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    Graduate Visualize what chirality physically means

    Yes I know. But in treatment of exciton states in quantum dot, a Hamiltonian describing hole-electron coupling is necessary. See for example http://www.sciencemag.org/cgi/content/abstract/291/5503/451
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    High School What does the electrical conductivity of the elements depends from?

    Many... First off, the phase it is in.
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    Graduate Visualize what chirality physically means

    Well.. you cannot get the full bandstructure with methods like k.p. or Dirac equation. But it allows you to describe the states in the vicinity of the band minima depending on where you do your k.p expansion. As a matter of fact, Dirac equation for graphene can be obtained from a k.p expansion...
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    Graduate Visualize what chirality physically means

    I disagree. Graphene has a energy dispersion relationship just like any material. Its just that it has a UNIQUE dispersion relationship. The chirality aspect of graphene should exist in usual semiconductors like Si. Nothing can stop you if you insist to use a Dirac equation to describe the E-K...
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    Graduate Visualize what chirality physically means

    In the usual treatment of graphene, people usually use a Dirac equation for describing the bandstructure which introduces chirality into the eigenstates. So, this results in the conduction and valence band electron states having opposite chirality. But frankly, I do not grasp the physical...
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    Graduate Visualize what chirality physically means

    see example this http://arxiv.org/abs/cond-mat/0604323
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    Graduate What is the Fermion Moving at Light Speed?

    it moves with speed of light. it is a fermion.
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    Graduate Visualize what chirality physically means

    My difficultly is in trying to visualize what chirality physically means. In solid state system, people usually ascribed electron of one chirality to be electron in the conduction band while the opposite chirality belongs to an unoccupied state (hole) in the valence band. Can I then say the...
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    Graduate How do one describe particles with chirality?

    Thank you for the reply. My difficultly is in trying to visualize what chirality physically means. In solid state system, people usually ascribed electron of one chirality to be electron in the conduction band while the opposite chirality belongs to an unoccupied state (hole) in the valence...
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    Graduate How is electron formed? Why does it travel?

    I think the picture of electron cloud spinning around the nuclues should be physical
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    Graduate How is electron formed? Why does it travel?

    proton's coulomb potential confined the electron cloud. But the electron cloud density in the nuclues center is zero.