Plebeian
Member
OK, I understand what it is (in terms of phonons etc.) but how does it lead to superconductivity? What is so special about Cooper pairs that enables them to travel without resistance? Any explanation would be appreciated.
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BCS Theory (1 Viewer)
- Thread starter Plebeian
- Start date
Plebeian
Member
OK thanks, I can't find any more than that so I suppose that's all we have to know.
boz
CEO
In 1957, a team of three scientists, John Bardeen, Leon Cooper and Robert Schrieffer proposed the first plausible explanation of superconductivity. They proposed that at very low temperatures the carriers of electricity are not single electrons, but pairs of electrons called Cooper pairs. Whilst normally the like charges would repel each other, Cooper pairs act like single particles with conducting properties very different from those of single electrons.
The process with which superconductivity occurs is called an electron-lattice-electron interaction. The first electron of the pair attracts the positive ions in the crystal lattice of the superconductor. These ions move inwards from their equilibrium positions. This distorted region of the lattice has a net positive charge, which then attracts the second electron to it. You cannot change the velocity of one Cooper pair without changing the velocity of them all, as they move through the lattice as a group. Vibrations or imperfections in the crystal lattice have no effect on the movement of the Cooper pairs. Cooper pairs are unusual because unlike in normal conductors, lattice vibrations reduce resistance and in fact help the flow of electricity. The diagram below shows how Cooper pairs move through a crystal lattice.
something also about phonons or packets of sound energy linking the two electrons together so that they, rather than reppel each other, act as a single entity.
The process with which superconductivity occurs is called an electron-lattice-electron interaction. The first electron of the pair attracts the positive ions in the crystal lattice of the superconductor. These ions move inwards from their equilibrium positions. This distorted region of the lattice has a net positive charge, which then attracts the second electron to it. You cannot change the velocity of one Cooper pair without changing the velocity of them all, as they move through the lattice as a group. Vibrations or imperfections in the crystal lattice have no effect on the movement of the Cooper pairs. Cooper pairs are unusual because unlike in normal conductors, lattice vibrations reduce resistance and in fact help the flow of electricity. The diagram below shows how Cooper pairs move through a crystal lattice.
something also about phonons or packets of sound energy linking the two electrons together so that they, rather than reppel each other, act as a single entity.