Insulator-to-metal Mott transition facilitated by lattice deformation in monolayer $\alpha$-RuCl${}_3$ on graphite

Abstract

Creating heterostructures with graphene/graphite is a practical method for charge-doping $\alpha$-RuCl${}_3$, but not sufficient to cause the insulator-to-metal transition. In this study, detailed scanning tunneling microscopy/spectroscopy measurements on $\alpha$-RuCl${}_3$ with various lattice deformations reveal that both in-plane and out-of-plane lattice distortions may collapse the Mott-gap in the case of monolayer $\alpha$-RuCl${}_3$ in proximity to graphite, but have little impact on its bulk form alone. In the Mott-Hubbard framework, the transition is attributed to the lattice distortion-facilitated substantial modulation of the electron correlation parameter. Observation of the orbital textures on a highly compressed monolayer $\alpha$-RuCl${}_3$ flake on graphite provides valuable evidence that electrons are efficiently transferred from the heterointerface into Cl3$p$ orbitals under the lattice distortion. It is believed that the splitting of Ru $t_{2g}$ bands within the trigonal distortion of Ru-Cl-Ru octahedra bonds generated the electrons transfer pathways. The increase of the Cl3$p$ states enhance the hopping integral in the Mott-Hubbard bands, resulting in the Mott-transition. These findings suggest a new route for implementing the insulator-to-metal transition upon doping in $\alpha$-RuCl${}_3$ by deforming the lattice in addition to the formation of heterostructure.

9 pages, 5 figures, Accepted for publication in Physical Review B

References in corpus (17)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• A `checkerboard' electronic crystal state in lightly hole-doped Ca_{2-x}Na_{x}CuO_{2}Cl_{2}
• Graphene/$\alpha$-RuCl${}_3$: An Emergent 2D Plasmonic Interface
• Spin-split band hybridization in graphene proximitized with $\alpha$-RuCl${}_3$ nanosheets
• Doping dependent charge order correlations in electron-doped cuprates
• Electronic Structure of the Kitaev Material $\alpha$-${\text{RuCl}}_3$ Probed by Photoemission and Inverse Photoemission Spectroscopies
• Charge ordering in superconducting copper oxides
• Possible strain induced Mott gap collapse in 1T-TaS${}_2$
• Magnetoelastic coupling and effects of uniaxial strain in $\alpha$-RuCl${}_3$ from first principles
• Phase separation in doped Mott insulators
• Mott Quantum Critical Points at finite doping
• Direct visualization of the charge transfer in Graphene/$\alpha$-RuCl${}_3$ heterostructure
• Tunneling spectroscopic signatures of charge doping and associated Mott transition in $\alpha$-RuCl${}_3$ in proximity to graphite
• Magnetic anisotropy energies and metal-insulator transitions in monolayers of $\alpha$-RuCl${}_3$ and OsCl${}_3$ on graphene
• Contrasting electronic states of RuI3 and RuCl3
• Phase diagram for Hole-Doped Kitaev System on the Honeycomb Lattice

Cited by in corpus (2)

• Kitaev Quantum Spin Liquids
• Mott Gap Softening Coinciding with Spin Correlations Collapse in a-RuCl3