Rich unconventional Hall effects in a single quasi-kagome Kondo Weyl semimetal candidate Ce$_3$TiSb$_5$

TL;DR

This paper reports the observation of multiple unconventional Hall effects in the quasi-kagome Kondo Weyl semimetal candidate Ce$_3$TiSb$_5$, revealing complex interplay among electronic correlation, geometric frustration, and topology.

Contribution

It presents the first detailed experimental study of diverse Hall effects in a single compound, linking them to magnetic textures and topological features.

Findings

Large topological Hall effect exceeding 0.2 μΩ·cm at low temperatures.

Signature of dynamic c-f hybridization affecting anomalous Hall effect.

Observation of a loop-shaped Hall effect linked to magnetic domain walls.

Abstract

It is generally believed that electronic correlation, geometric frustration, and topology, \textit{individually}, can facilitate the emergence of various intriguing properties that have attracted a broad audience for both fundamental research and potential applications. Here, we report a series of unconventional Hall effects observed in a \textit{single} compound - quasi-kagome Kondo Weyl semimetal candidate Ce$_3$TiSb$_5$. In the paramagnetic phase, signature of dynamic $c$-$f$ hybridization is revealed by a reduction of anomalous Hall effect and is connected to frustration-promoted incoherent Kondo scattering. A large topological Hall effect exceeding 0.2 $\mu\Omega\cdot$cm is found at low temperatures, which should be ascribed to the non-collinear magnetic texture. In addition, a peculiar loop-shaped Hall effect with switching chirality is also seen, which is inferred to be associated with magnetic domain walls that pin history-dependent spin chirality and / or Fermi-arc surface states projected from the in-gap Weyl nodes. These exotic results place Ce$_3$TiSb$_5$ in a regime of highly-frustrated antiferromagnetic dense Kondo lattice with a nontrivial topology on an ``extended" global phase diagram, and highlight the interplay among electronic correlation, geometric frustration and topology.