Dimensionality reduction and band quantization induced by potassium intercalation in 1$T$-HfTe${}_2$

Abstract

We have performed angle-resolved photoemission spectroscopy on transition-metal dichalcogenide 1$T$-HfTe${}_2$ to elucidate the evolution of electronic states upon potassium (K) deposition. In pristine HfTe${}_2$, an in-plane hole pocket and electron pockets are observed at the Brillouin-zone center and corner, respectively, indicating the semimetallic nature of bulk HfTe${}_2$, with dispersion perpendicular to the plane. In contrast, the band structure of heavily K-dosed HfTe${}_2$ is obviously different from that of bulk, and resembles the band structure calculated for monolayer HfTe${}_2$. It was also observed that lightly K-dosed HfTe${}_2$ is characterized by quantized bands originating from bilayer and trilayer HfTe${}_2$, indicative of staging. The results suggest that the dimensionality-crossover from 3D (dimensional) to 2D electronic states due to systematic K intercalation takes place via staging in a single sample. The study provides a new strategy for controlling the dimensionality and functionality of novel quantum materials.

7 pages, 4 figures

References in corpus (22)

• Two-Dimensional Gas of Massless Dirac Fermions in Graphene
• Atomically thin MoS2: A new direct-gap semiconductor
• Two Dimensional Atomic Crystals
• Control of valley polarization in monolayer MoS2 by optical helicity
• Valley polarization in MoS2 monolayers by optical pumping
• MoS_2 as an ideal material for valleytronics: valley-selective circular dichroism and valley Hall effect
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• The Valley Hall Effect in MoS2 Transistors
• Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2
• Interface induced high temperature superconductivity in single unit-cell FeSe films on SrTiO3
• Evidence of Ising pairing in superconducting NbSe${}_2$ atomic layers
• Quasi-free Standing Epitaxial Graphene on SiC by Hydrogen Intercalation
• Two Dimensional Ising Superconductivity in Gated MoS${}_2$
• Strongly enhanced charge-density-wave order in monolayer NbSe${}_2$
• Realization of Quantum Spin Hall State in Monolayer 1T'-WTe2
• Observation of the Quantum Spin Hall Effect up to 100 Kelvin in a Monolayer Crystal
• Edge conduction in monolayer WTe2
• Superconductivity protected by spin-valley locking in ion-gated MoS2
• Universal Mechanism of Band-Gap Engineering in Transition-Metal Dichalcogenides
• Molecular Beam Epitaxy of thin HfTe2 semimetal films
• Narrow-band anisotropic electronic structure of ReS${}_2$
• Direct observation of strain-induced orbital valence band splitting in HfSe${}_2$ by sodium intercalation

Cited by in corpus (7)

• Emergence of Topologically Non-trivial Spin-polarized States in a Segmented Linear Chain
• Observation of possible excitonic charge density waves and metal-insulator transitions in atomically thin semimetals
• Enhanced superconductivity in bilayer PtTe${}_2$ by alkali-metal intercalations
• Bulk and surface electronic states in the dosed semimetallic HfTe${}_2$
• In-situ topotactic chemical reaction for spectroscopies
• Shubnikov-de Haas oscillations and planar Hall effect in HfTe2
• Intercalation induced quasi-freestanding layer in TiSe${}_2$