In reply to [EMAIL PROTECTED]'s message of Sat, 23 Feb 2008 18:16:41 EST: Hi Frank, [snip] >Assuming your coherence length is at least proportional to the De Broglie >wavelength (L_DB) and > >L_DB = h/p and > >p = sqrt(2*m*E) where E = kinetic energy, we get > >L_DB = h/(sqrt(2*m*E)) . > >Since, as you state above, the energy is "the same" irrespective of type of >particle, we see that L_DB is in fact shorter for heavy particles than it is >for >light ones (the mass is in the denominator). IOW I would expect the coherence >length of electrons to be sqrt(1836) ~= 43 times greater than that of >protons. > >IOW I think your quest for heavier particles may be misguided. > > >I believe that you are way off using the deBroglie wavelength as the >coherence length. >In superconductors the state of the electron can equal the length of the >superconductor.
Do you have a reference for this? All those, that I could find, mentioned the coherence length in superconductors as exceeding the distance between the electrons in a pair (not difficult). >This is much longer than the deBroglie waveleigth. The De Broglie wavelength at 4 K is about 66 nm, which seems about right, if the inter electron pair distance is to be less than this. >I believe that the coherence length is equal to the downshifted Compton >wavelength. Do you have a formula for this, and how does it differ from the definition of the De Broglie wavelength? BTW, did you notice the "Fermi velocity"? Regards, Robin van Spaandonk The shrub is a plant.
