Massive and massless charge carriers in an epitaxially strained alkali metal quantum well on graphene

Abstract

We show that Cs intercalated bilayer graphene acts as a substrate for the growth of a strained Cs film hosting quantum well states with high electronic quality. The Cs film grows in an fcc phase with a substantially reduced lattice constant of 4.9 Å corresponding to a compressive strain of 11% compared to bulk Cs. We investigate its electronic structure using angle-resolved photoemission spectroscopy and show the coexistence of massless Dirac and massive Schrödinger charge carriers in two dimensions. Analysis of the electronic self-energy of the massive charge carriers reveals the crystallographic direction in which a twodimensional Fermi gas is realized. Our work introduces the growth of strained metal quantum wells on intercalated Dirac matter.

Mechanical, electronic, optical, piezoelectric and ferroic properties of strained graphene and other strained monolayers and multilayers: an update

“…Massive and massless charge carriers were observed on caesium-doped graphene; a system modelled as a strained quantum well [154]. Extended flat bands were reported for this system in a later work [155].…”

“…A proposal by Ghazaryan et al [356] pointed out a general mechanism for superconductivity induced by an annular Fermi surface. Remarkably, an annular Fermi surface has not only been observed in ABC-trilayer graphene, but in other graphene superlattices [154] as well.…”

Quasi‐Homoepitaxial Growth of Highly Strained Alkali‐Metal Ultrathin Films on Kagome Superconductors

“…We note that a recent study reported that single-crystalline fcc Cs thin films are stabilized on Cs-intercalated bilayer graphene due to the adhesion energy between Cs and the bilayer graphene substrate. [46] However, in this heterostructure, only 3 ML Cs film has been obtained experimentally so far. [46] In contrast, we have successfully controlled the film thickness up to at least 30 MLs (Figure 3).…”

Thermodynamically Driven Formation of Intercalated Cu Carpets from Supported Cu Pyramids on MoS2

“…Intercalation of foreign guest species in transition metal dichalcogenides (TMDs), such as MoS 2 , WS 2 , MoSe 2 , WSe 2 , et al, is beginning to attract considerable interest. This is in part due to the novel electronic properties of these systems enabling prospective applications to high-performance electronics, optoelectronics, electrochemical catalysis, energy storage and conversion (such as ionic batteries), and biological systems. − In this context, studies of intercalation specifically for MoS 2 have attracted considerable attention. , On the other hand, TMD nanosheets are often fabricated by intercalation, and various methods toward this goal have been utilized. , Also, there do already exist extensive studies of near-surface intercalation in other types of layered van der Waals (vdW) materials, including graphite (or multilayer graphene) and SiC- , or metal-supported graphene layers. The above studies − generally involve homogeneously distributed intercalant atoms in the TMD interlayer spaces.…”

“…8,9 On the other hand, TMD nanosheets are often fabricated by intercalation, and various methods toward this goal have been utilized. 10,11 Also, there do already exist extensive studies of near-surface intercalation in other types of layered van der Waals (vdW) materials, including graphite (or multilayer graphene) 12 and SiC- 13,14 or metal-supported 15 graphene layers. The above studies 1−11 generally involve homogeneously distributed intercalant atoms in the TMD interlayer spaces.…”