Year: 2026
Type: preprint
Abstract: Fractional changes in entropy are often associated with strong electron correlations or non-Abelian anyons in topological systems. We show that neither condition is necessary -- a system of free electrons on a ring scattering off a repulsive point-like impurity undergoes a $k_B\ln\sqrt 2$ entropy change as the impurity strength is increased. This effect arises from a shift of allowed single-particle momenta from integer quantization to half-integer quantization, induced by the impurity. We show that this fractional entropy change is universal across a broad class of single-particle dispersions, demonstrating that such signatures can arise without strong correlations or topological order.
Source: arXiv (Cornell University)
Authors: Zaidi, Syeda Neha, Väyrynen, Jukka I.
Institution: Purdue University West Lafayette
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204963519