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Difference between Superconductivity & Ballistic Conduction

  1. May 29, 2015 #1
    I read in a book "Optoelectronic Integration: Physics, Technology and Applications" edited by Osamu Wada.

    Ballistic Conduction and Superconductivity are both electron transport that are not affected by the collisions and scatterings.

    Ballistic conduction or Ballistic transport occurs when the mean free path of the electron is (much) longer than the dimension of the medium through which the electron travels. Hence there is no chance of electrons collisions. No energy dissipated during conduction.

    Superconductivity is the result of a quantum mechanical effect that avoids the collision and scattering. In the superconductive state, all the mobile electrons cooperate together to form a coherent state (Cooper pair) as whole. If the coherent state is sufficiently lower in energy than the usual normal state, it is hardly destroyed by the collisions or scatterings.


    Although both are electron transport that are not affected by the collisions and scatterings but ballistic conduction differs from superconductivity due to the absence of the Meissner effect in the material. A ballistic conductor would stop conducting if the driving force is turned off, whereas in a superconductor current would continue to flow after the driving supply is disconnected.

    And another difference I can think is charge carriers in Ballistic transport are electrons which act as Fermions.
    In Superconductor charge carrier are Cooper pair and it behave as Bosons.

    Can anyone elaborate the difference between the two?
  2. jcsd
  3. May 30, 2015 #2


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    There is still a chance, and the chance increases if you increase the length of the material - exactly as resistance increases in regular conductors. Very thin sheets of material have a low resistance, that is not superconductivity but simple scaling of resistances.
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