Distinguishing a Mott Insulator from a Trivial Insulator with Atomic Adsorbates

Abstract

In an electronic system with various interactions intertwined, revealing the origin of its many-body ground state is challenging and a direct experimental way to verify the correlated nature of an insulator has been lacking. Here we demonstrate a way to unambiguously distinguish a paradigmatic correlated insulator, a Mott insulator, from a trivial band insulator based on their distinct chemical behavior for a surface adsorbate using 1T-TaS2, which has been debated between a spin-frustrated Mott insulator or a spin-singlet trivial insulator. We start from the observation of different sizes of spectral gaps on different surface terminations and show that potassium adatoms on these two surface layers behave in totally different ways. This can be straightforwardly understood from distinct properties of a Mott and a band insulators due to the fundamental difference of a half and a full-filled orbital involved respectively. This work not only solves an outstanding problem in this particularly interesting material but also provides a simple touchstone to identify the correlated ground state of electrons experimentally.

6 pages, 4 figures

References in corpus (5)

• Band insulator to Mott insulator transition in 1T-TaS${}_2$
• Gapless excitations in the ground state of 1T-TaS${}_2$
• Correlated electronic states at domain walls of a Mott-charge-density-wave insulator 1T-TaS2
• Surface structure and stacking of the commensurate $\left(\sqrt{13}\times \sqrt{13}\right)$R13.9° charge density wave phase of 1T-TaS${}_2$(0001)
• Honeycomb-Lattice Mott insulator on Tantalum Disulphide

Cited by in corpus (29)

• Effect of Stacking Order on the Electronic State of 1T-TaS${}_2$
• Mott versus hybridization gap in the low-temperature phase of $1T$-TaS${}_2$
• Inducing and tuning Kondo screening in a narrow-electronic-band system
• Magnetic Impurity as a Local Probe of the U(1) Quantum Spin Liquid with Spinon Fermi Surface
• $\text{Ab initio}$ theory of magnetism in two-dimensional $1T$-TaS${}_2$
• Reconcile the Bulk Metallic and Surface Insulating state in 1T-TaSe${}_2$
• Probing quantum spin liquids with a quantum twisting microscope
• Modified interlayer stacking and insulator to correlated-metal transition driven by uniaxial strain in 1$T$-TaS${}_2$
• Charge density wave surface reconstruction in a van der Waals layered material
• Photo-induced charge dynamics in 1$T$-TaS${}_2$
• Optical Distinguishability of Mott Insulators in Time vs Frequency Domain
• Charge ordered phases in the hole-doped triangular Mott insulator 4Hb-TaS2
• Origin of Distinct Insulating Domains in the Layered Charge Density Wave Material 1T-TaS2
• Mobile Kink Solitons in a Van der Waals Charge-Density-Wave Layer
• Spectroscopic evidence for possible quantum spin liquid behavior in a two-dimensional Mott insulator
• Dimensional crossover of charge order in IrTe${}_2$ with strong interlayer coupling
• Distinguishing and controlling Mottness in 1T-TaS${}_2$ by ultrafast light
• Direct evidence of intrinsic Mott state and its layer-parity oscillation in a breathing kagome crystal down to monolayer
• Momentum-Resolved Fingerprint of Mottness in Layer-Dimerized Nb${}_3$Br${}_8$
• Interlayer Hopping between Surface Mott Insulator and Bulk Band Insulator in layered 1T-TaS_{2}
• Probing complex stacking in a layered material via electron-nuclear quadrupolar coupling
• Behavior under magnetic field of resonance at the edge of the upper Hubbard band in 1T-TaS2
• Interplay of broken symmetry and delocalized excitations in the insulating state of 1$T$-TaS${}_2$
• Emergent Quantum Phenomena of Noncentrosymmetric Charge-Density Wave in 1T-Transition Metal Dichalcogenides
• Comment on "Identification of the Mott Insulating Charge Density Wave State in $1T$-TaS${}_2$"
• Topical review: the nature of the ground state and possibility of a quantum spin liquid in 1T metal dichalcogenides
• Toward nonthermal control of excited quantum materials: framework and investigations by ultrafast electron scattering and imaging
• Emergent quantum phenomena in two-dimensional 1T-TaS2
• Giant Optomechanical Coupling in the Charge Density Wave State of Tantalum Disulfide