Large-gap insulating dimer ground state in monolayer IrTe2

Abstract

Monolayers of two-dimensional van der Waals materials exhibit novel electronic phases distinct from their bulk due to the symmetry breaking and reduced screening in the absence of the interlayer coupling. In this work, we combine angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy to demonstrate the emergence of a unique insulating 2 x 1 dimer ground state in monolayer 1T-IrTe2 that has a large band gap in contrast to the metallic bilayer-to-bulk forms of this material. First-principles calculations reveal that phonon and charge instabilities as well as local bond formation collectively enhance and stabilize a charge-ordered ground state. Our findings provide important insights into the subtle balance of interactions having similar energy scales that occurs in the absence of strong interlayer coupling, which offers new opportunities to engineer the properties of 2D monolayers.

References in corpus (26)

• Atomically thin MoS2: A new direct-gap semiconductor
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Optical Spectrum of MoS${}_2$: Many-body Effects and Diversity of Exciton States
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2
• Realization of Quantum Spin Hall State in Monolayer 1T'-WTe2
• Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
• Classification of Charge Density Waves Based on Their Nature
• Observation of a $d$-wave gap in electron-doped Sr${}_2$IrO${}_4$
• Visualizing Exotic Orbital Texture in the Single-Layer Mott Insulator 1T-TaSe2
• Emergence of a Metal-Insulator Transition and High Temperature Charge Density Waves in VSe2 at the Monolayer Limit
• Unique gap structure and symmetry of the charge density wave in single-layer VSe${}_2$
• Orbital physics in transition metal compounds: new trends
• Physical origin of giant excitonic and magneto-optical responses in two-dimensional ferromagnetic insulators
• Imaging spinon density modulations in a 2D quantum spin liquid
• Dimerization-Induced Cross-Layer Quasi-Two-Dimensionality in Metallic Iridate IrTe2
• Anionic depolymerization transition in IrTe2
• Evidence of charge density wave with anisotropic gap in monolayer VTe${}_2$ film
• Local orbital degeneracy lifting as a precursor to an orbital-selective Peierls transition
• Hysteretic melting transition of a soliton lattice in a commensurate charge modulation
• Electronic structure and magnetic properties of few-layer Cr${}_2$Ge${}_2$Te${}_6$: the key role of nonlocal electron-electron interaction effects
• Spin-orbit-controlled metal-insulator transition in Sr${}_2$IrO${}_4$
• Superconductivity emerging from a stripe charge order in IrTe2 nanoflakes

Cited by in corpus (7)

• Realization of multiple charge density waves in NbTe2 at the monolayer limit
• Ferroelectricity-tuned band topology and superconductivity in two-dimensional materials and related heterostructures
• A novel $\sqrt{19}\times \sqrt{19}$ superstructure in epitaxially grown 1T-TaTe${}_2$
• Metastable polymorphic phases in monolayer TaTe2
• Unusual ferromagnetic band evolution and high Curie temperature in monolayer 1T-CrTe2 on bilayer graphene
• Dimensional crossover of charge order in IrTe${}_2$ with strong interlayer coupling
• In-situ scanning tunneling microscopy observation of thickness-dependent air-sensitive layered materials and heterodevices