Coulomb Universality
Leo Radzihovsky
University of Colorado
Wednesday, October 23, 2024
11:00 a.m.
In-person: QNC 1101
Abstract: Motivated by a number of realizations of long-range interacting systems, I will discuss a neutral plasma with power-law interactions longer-ranged than Coulombic. I will show that beyond a crossover length, such interactions are universally screened down to a standard Coulomb form in all spatial dimensions. This implies, counterintuitively, that in two dimensions and below, such a “super-Coulombic” gas is asymptotically confining at low temperatures and undergoes a deconfining transition that in two dimensions is the same Kosterlitz-Thouless transition as a conventional Coulomb gas. I will also explain that the super-Coulomb to Coulomb crossover is followed at longer length scales by an unconventional ”Debye-Huckel” screening, which leads to faster-than-Coulombic, power-law decay of the screened potential, in contrast to the usual exponentially decaying Yukawa potential. I will conclude with showing absence of such universal screening in a related XY model with power-law exchange.