Heavy-Fermion Behavior and a Tunable Density Wave in a Novel Vanadium-based Mosaic Lattice

TL;DR

This paper reports a novel vanadium-based lattice compound, Cs3V9Te13, exhibiting heavy fermion behavior and a tunable density wave, serving as a platform for exploring correlated electronic states.

Contribution

Discovery of a new intermetallic compound with a unique mosaic lattice that demonstrates heavy fermion physics and tunable density wave phenomena.

Findings

Cs3V9Te13 exhibits a large Sommerfeld coefficient indicating heavy fermion behavior.

Chemical pressure via Rb substitution suppresses the density wave and weakens heavy-electron response.

The ground state can be tuned from density wave order to a quantum-disordered state.

Abstract

The pursuit of geometrically frustrated lattices beyond conventional paradigms remains a central challenge in the design of quantum materials. Herein, we report the discovery of Cs3V9Te13 (CVT), a novel intermetallic compound that hosts a unique two-dimensional vanadium mosaic lattice, composed of an ordered tessellation of triangles, squares, and pentagons, bearing profound structural kinship with the celebrated kagome lattice. Remarkably, CVT exhibits behavior analogous to heavy fermion systems, characterized by a large Sommerfeld coefficient({\gamma} = 425 mJ mol-1 K-2) and a coherent density-wave-like (DW-like) transition at T* = 47 K. This establishes CVT as a rare and intriguing example of a strongly correlated system. Inspired by pressure-tuning in related compounds, we demonstrate that this ground state is exquisitely tunable via chemical pressure. Systematic substitution of Cs with smaller Rb ions suppresses the DW-like order while strongly weakening the heavy-electron response, ultimately driving the system into a distinct non-magnetic, semiconducting, quantum-disordered state above 60 mK. This work unveils a new arena for exploring the interplay between heavy-fermion physics, density waves, and quantum disorder. The mosaic lattice in Cs3V9Te13 provides an unprecedented, chemically controllable platform for navigating the phase space between distinct correlated electronic states.