Glassy Relaxation Dynamics in the Two-Dimensional Heavy Fermion Antiferromagnet CeSiI

TL;DR

This study explores the magnetic and electronic properties of atomically thin CeSiI, revealing its two-dimensional heavy fermion and antiferromagnetic behavior, along with glassy relaxation dynamics indicative of complex magnetic phases.

Contribution

It provides the first detailed investigation of magnetic properties and glassy dynamics in 2D CeSiI, highlighting its potential for studying quantum criticality and magnetic phase interplay.

Findings

Thickness-dependent magnetotransport confirms 2D heavy fermion behavior.

Observation of isotropic, time-dependent hysteresis in magnetoresistance and Hall resistance.

Evidence of glassy relaxation dynamics in magnetic responses.

Abstract

The recent discovery of the van der Waals (vdW) layered heavy fermion antiferromagnetic metal CeSiI offers promising potential for achieving accessible quantum criticality in the two-dimensional (2D) limit. CeSiI exhibits both heavy fermion behavior and antiferromagnetic (AFM) ordering, while the exact magnetic structure and phase diagram have yet to be determined. Here, we investigate magnetic properties of atomically thin CeSiI devices with thicknesses ranging from 2-15 vdW layers. The thickness-dependent magnetotransport measurement reveals an intrinsic 2D nature of heavy fermion behavior and antiferromagnetism. Notably, we also find an isotropic, time-dependent hysteresis in both magnetoresistance and Hall resistance, showing glassy relaxation dynamics. This glassy behavior in magnetic structures may suggest the presence of spin glass phases or multipolar ordering, further establishing CeSiI as an intriguing material system for investigating the interplay between magnetic orders and the Kondo effect.