Recent content by Zymandia

  1. Z

    How Does the London Moment Behave Near a Spinning Superconductor's Surface?

    What does the field of the London Moment do as it approaches the surface of the spinning SC? A: Continue to the surface undiminished then fade away in a few penetration lengths, exactly as though it were an exterior field being applied to a stationary SC. B: Start fading away a few...
  2. Z

    Ginzberg-Landau and the Cooper Pair

    "The supercurrent has a WHOLE RANGE OF k! That was how I answered your question, but you didn't have a clue what that meant, obviously." No I don't have a clue, and attempts to find-out just finds high-phalutin' physicists giving hand-waving explanations of the 'super-current'. So let's use...
  3. Z

    Ginzberg-Landau and the Cooper Pair

    You have not answered the question. How do high k short-wavelength constituents of a Cooper Pair tunnel over > 1000 wave-lengths without the barrier potential attenuating them to nothing. Simple basic quantum mechanics is all that is needed for a v. low k single wave-function.
  4. Z

    Ginzberg-Landau and the Cooper Pair

    I do understand current theory but I think there is a lot of phenomenological evidence to show that the two electron Cooper Pair is wrong. Long-distance JJ tunnelling is simply explained if we have a single very long wave-length, ie. low |k|, wave-function performing normal QM tunneling through...
  5. Z

    Ginzberg-Landau and the Cooper Pair

    I've thought hard on whether one can take a group of fermions and by considering them as pairs declare them bosonic. It seems to me that the pairing to a quasi-particle requires that the quasi-particle wave-function be unique for a given point which seems unlikely since its substructure (the 2...
  6. Z

    Ginzberg-Landau and the Cooper Pair

    In normal BCS compliant superconductivity the phonon that breaks the Pair (not the weird thing that holds the pair together) is surely a normal F-D thermal phonon? In the HTSCs the problem is that they survive to temperatures where kT is much bigger than the superconducting gap. Currently this...
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    Ginzberg-Landau and the Cooper Pair

    Hmm, two swaps on a wave-function will always be symmetric even for an anti-symmetric wave-function. Your original 4 electron state is plainly fermionic since swapping any single pair of particles will be anti-symmetric. However you are saying that we can declare two fermions to be a single...
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    Ginzberg-Landau and the Cooper Pair

    "If we read original Ginzburg-Landau paper carefully," I can't find an english language link (and the russian link didn't work), is it up anywhere? Also can anyone point me at some cuprate critical field/temp plots for various samples? There is a kink at < 20K for the higher Tc samples (> 70K)...
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    Ginzberg-Landau and the Cooper Pair

    If it is a 'SINGLE LARGE COMPLEX PARTICLE/WAVE' then it wouldn't obey the Pauli Exclusion Principle with regard to the surrounding lattice electrons/Brouillin Zone??
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    Ginzberg-Landau and the Cooper Pair

    Run that by me again. How does one swap pick up two negative signs?
  11. Z

    Ginzberg-Landau and the Cooper Pair

    "I take the view that quantum mechanics says N is just a quantum number of the bose field" "For quasiparticles to be bosonic, you need the wavefunction to symmetric under exchange of the quasiparticles, not the constituent particles. This is true regardless of whether they have fermionic or...
  12. Z

    Ginzberg-Landau and the Cooper Pair

    Tate Paper at: http://prola.aps.org/abstract/PRL/v62/i8/p845_1
  13. Z

    Ginzberg-Landau and the Cooper Pair

    But it is generally accepted that two fermions can team up to form a boson" The 'team up' is the crux. A pion is a boson formed of two fermions that are so heavily interacting that it would be meaningless to ask about its constituents before it decayed. However if we talk about a bosonic...
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    Ginzberg-Landau and the Cooper Pair

    While they have indentifiably fermionic constituents they cannot have an overall symmetric wave-function surely. Only down at the milliKelvins can whole atoms become so indistinct that bosonic behaviour is seen, indeed it seems to me that the bosonic / fermionic phase change at critical...
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    Ginzberg-Landau and the Cooper Pair

    If they are bosonic quasi-particles then they may not have fermionic constituents. It seems to me from the abstract that these guys are trying to have their cake and eat it. They are suggesting that a collection of Cooper Pairs maybe considered a BEC while the electrons remain fermions. If the...
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