Frustrated S = 1/2 Chains in One-Dimensional Correlated Metal Ti4MnBi2

TL;DR

This paper demonstrates that Ti4MnBi2 is a metallic one-dimensional spin chain with frustrated magnetism, where 3D conduction electrons strongly couple to 1D magnetic moments, revealing a new quantum critical behavior in correlated metals.

Contribution

It provides the first evidence of a metallic spin chain with 1D magnetism and strong electron-moment coupling, near a quantum critical point.

Findings

Spinons confirmed in Ti4MnBi2 via neutron scattering and DMRG.

Ti4MnBi2 exhibits 1D magnetism dominated at low temperatures.

Strong coupling between conduction electrons and 1D magnetic moments.

Abstract

Electronic correlations lead to heavy quasiparticles in three-dimensional (3D) metals, and their collapse can destabilize magnetic moments. It is an open question whether there is an analogous instability in one-dimensional (1D) systems, unanswered due to the lack of metallic spin chain materials. We report neutron scattering measurements and Density Matrix Renormalization Group calculations establishing spinons in the correlated metal Ti4MnBi2, confirming that its magnetism is 1D. Ti4MnBi2 is inherently frustrated, forming near a quantum critical point (QCP) separating different temperature T = 0 phases of the J1-J2 XXZ model. 1D magnetism dominates to the lowest T, and is barely affected by weak interchain coupling. Ti4MnBi2 is the first metallic spin chain where 3D conduction electrons become strongly correlated due to their coupling to 1D magnetic moments.