Nearly-free-electron system of monolayer Na on the surface of single-crystal HfSe${}_2$

Abstract

The electronic structure of a single Na monolayer on the surface of single-crystal HfSe${}_2$ is investigated using angle-resolved photoemission spectroscopy. We find that this system exhibits an almost perfect "nearly-free-electron" behavior with an extracted effective mass of $\sim 1m_e$, in contrast to heavier masses found previously for alkali metal monolayers on other substrates. Our density-functional-theory calculations indicate that this is due to the large lattice constant, causing both exchange and correlation interactions to be suppressed, and to the weak hybridization between the overlayer and the substrate. This is therefore an ideal model system for understanding the properties of two-dimensional materials.

arXiv comment5 pages, 3 figures

References in corpus (14)

• Control of valley polarization in monolayer MoS2 by optical helicity
• MoS_2 as an ideal material for valleytronics: valley-selective circular dichroism and valley Hall effect
• Field-effect tunneling transistor based on vertical graphene heterostructures
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2
• Non-ballistic spin field-effect transistor
• Creation and control of a two-dimensional electron liquid at the bare SrTiO3 surface
• Large tuneable Rashba spin splitting of a two-dimensional electron gas in Bi2Se3
• Large capacitance enhancement and negative compressibility of two-dimensional electronic systems at LaAlO${}_3$/SrTiO${}_3$ interfaces
• Spin-orbit splitting of the Shockley surface state on Cu(111)
• Ultrafast Band Structure Control of a Two-Dimensional Heterostructure
• An alternate spintronic analog of the electro-optic modulator
• Spin- and valley- coupled electronic states in monolayer WSe2 on bilayer graphene
• Observation of momentum space semi-localization in Si-doped $\beta$-Ga${}_2$O${}_3$

Cited by in corpus (5)

• Dual quantum confinement and anisotropic spin splitting in the multi-valley semimetal PtSe${}_2$
• Bulk and surface electronic states in the dosed semimetallic HfTe${}_2$
• The Quantum Hall Effect with Wilczek's charged magnetic flux tubes instead of electrons
• Ultrafast Carrier Dynamics in Two-Dimensional Electron Gas-Like K-doped MoS2
• Orbital-selective metal skin induced by alkali-metal-dosing Mott-insulating Ca${}_2$RuO${}_4$