Even-denominator fractional quantum Hall states (FQHSs) fall outside the standard Laughlin's and Jain's odd-denominator hierarchy. In this work, we study the FQHS ν=1/2 in the lowest Landau level. The state is confined within a 70 nm-wide GaAs quantum well, where the electrons exhibit a bilayer-like charge distribution. Inter-layer interactions stabilize the ν=1/2 FQHS, which is predicted to host quasiparticles with charge e/4 - with either Abelian or non-Abelian topological order. Here, we report on shot-noise measurements of partitioned quasiparticles at ν=1/2, where charge partitioning is generated by a unique etch-defined quantum point contact. Our measurements were performed on two nominally identical devices, at two independent experimental setups. Analysis of shot noise in the weak-backscattering regime in each device reveals quasiparticles with charge e/4. These observations provide a clear benchmark for future studies aimed at probing the topological order of the ν=1/2 FQHS and its quasiparticles' exchange statistics.
@article{arxiv.2602.08468,
title = {Observation of e/4 charge at $\nu=1/2$ in GaAs},
author = {Tomer Alkalai and Emily Hajigeorgiou and Adbhut Gupta and Tapas Senapati and Priya Tiwari and Chia-Tse Tai and Siddharth Kumar Singh and Kirk W. Baldwin and Loren N. Pfeiffer and Mansour Shayegan and Mitali Banerjee and Moty Heiblum},
journal= {arXiv preprint arXiv:2602.08468},
year = {2026}
}