Experimental physicists have found evidence that electrical resistance caused by particle collisions may not keep rising forever. According to ScienceDaily, the effect appears to level off once collisions become strong enough.
The research team from the University of Toronto, L'École Normale Supérieure in Paris and Lehigh University studied ultracold potassium atoms cooled to nearly absolute zero. Using an optical lattice, a grid of light that traps atoms, they were able to mimic how electrons move through a solid while tightly controlling the collisions.
As the frequency of collisions increased, resistance rose at first. But beyond a certain point, the researchers saw it stop increasing, suggesting a possible upper limit to collision-driven resistivity.
Senior author Joseph Thywissen of the University of Toronto said the result gives a clearer microscopic picture of resistivity in low-density metals. The findings, published in Physical Review Letters, may also help guide future work on strongly correlated atomic systems and quantum materials.
