Crossover from 2D metal to 3D Dirac semimetal in metallic PtTe2 films with local Rashba effect

Abstract

PtTe2 and PtSe2 with trigonal structure have attracted extensive research interests since the discovery of type-II Dirac fermions in the bulk crystals. The evolution of the electronic structure from bulk 3D topological semimetal to 2D atomic thin films is an important scientific question. While a transition from 3D type-II Dirac semimetal in the bulk to 2D semiconductor in monolayer (ML) film has been reported for PtSe2, so far the evolution of electronic structure of atomically thin PtTe2 films still remains unexplored. Here we report a systematic angle-resolved photoemission spectroscopy (ARPES) study of the electronic structure of high quality PtTe2 films grown by molecular beam epitaxy with thickness from 2 ML to 6 ML. ARPES measurements show that PtTe2 films still remain metallic even down to 2 ML thickness, which is in sharp contrast to the semiconducting property of few layer PtSe2 film. Moreover, a transition from 2D metal to 3D type-II Dirac semimetal occurs at film thickness of 4-6 ML. In addition, Spin-ARPES measurements reveal helical spin textures induced by local Rashba effect in the bulk PtTe2 crystal, suggesting that similar hidden spin is also expected in few monolayer PtTe2 films. Our work reveals the transition from 2D metal to 3D topological semimetal and provides new opportunities for investigating metallic 2D films with local Rashba effect.

arXiv comment10 pages, 4 figures

References in corpus (10)

• Type-II Weyl Semimetals
• Computational 2D Materials Database: Electronic Structure of Transition-Metal Dichalcogenides and Oxides
• Hidden spin polarization in inversion-symmetric bulk crystals
• Lorentz-violating type-II Dirac fermions in transition metal dichalcogenide PtTe${}_2$
• Type-II Dirac fermions in the PtSe${}_2$ class of transition metal dichalcogenides
• Topological superconductivity in bilayer Rashba system
• High quality atomically thin PtSe2 films grown by molecular beam epitaxy
• Unconventional superconductivity in bilayer transition metal dichalcogenides
• Low-Temperature Eutectic Synthesis of PtTe2 with Weak Antilocalization and Controlled Layer Thinning
• Odd-parity superconductivity in bilayer transition metal dichalcogenides

Cited by in corpus (10)

• Observation of Negative THz Photoconductivity in Large Area Type-II Dirac Semimetal PtTe2
• Semiconductor materials stacks for quantum dot spin qubits
• Low-temperature synthesis and electrocatalytic application of large-area PtTe2 thin films
• Observation of spin-momentum-layer locking in centrosymmetric BiOI
• Enhanced superconductivity in bilayer PtTe${}_2$ by alkali-metal intercalations
• Giant Rashba splitting in PtTe/PtTe${}_2$ heterostructure
• Large spin Hall conductivity and excellent hydrogen evolution reaction activity in unconventional PtTe1.75 monolayer
• Interfacial superconductivity in the type-III heterostructure SnSe${}_2$/PtTe${}_2$
• Designer three-dimensional electronic bands in asymmetric transition metal dichalcogenide heterostructures
• Impact of the out-of-plane conductivity on spin transport evaluation in a van der Waals material