>[!summary] Caused in superconductors from cooling a metal close to absolute zero. They are when two electrons overcome their repulsion force and act like boson, appear as the same wave function. # Normal Current In normal flow there is resistance caused by electrons hitting atoms releasing energy to the atom. The atom vibrate and the metal heat up, you can read more on this in [[Resistance & Ohm Law]] and [[Current]]. ![[Screenshot 2025-06-08 at 5.42.21 PM.png]] >[!note] Explanation In a normal flow of current electrons reflect off an atom, where the atom absorbed some energy. This is resistance # How cooper Pairs Form When a material is cooled down to a low enough temperature a interesting things happens to elections. Originally electrons have spin ([[Properties of Quarks]]) which doesn't allow them to be in the same quantum state as the other due to Pauli exclusion principle and electrons being a fermion. ([[Fermion, Bosons & Pauli Exclusion Principle]]) ![[Screenshot 2025-06-08 at 5.36.20 PM.png]] >[!note] Explanation Example of electrons in a material. Electron attracts the nearest atoms near it. Electrons being fermions explains why electron repel one another. ![[Screenshot 2025-06-08 at 5.36.58 PM.png]] >[!note] Explanation After electrons leave the area which attacted the nearest atoms, that area become a high area of charge. Other electrons now chase that high area of charge. In super conductors because the area is cooled so much, the atoms do not shake as much. With less shake the electrons creates a higher area of positive charge (because it passes through between two positive charges and attracts both) the other electrons get attracted to this area. At long distances this attraction overcome the electron's repulsion form **cooper pairs** they act like one whole boson pair ![[Screenshot 2025-06-08 at 5.37.12 PM.png]] >[!note] Explanation Graphical picture of electron repulsions getting overcome and cooper pairs being formed. The squiggly line represents cooper pair formation. # Extra Resources I found this video by [Arvin Arsh](https://www.youtube.com/watch?v=vruYFOlM1-Q&ab_channel=ArvinAsh) helpful in understanding cooper pairs along with other theory.