Synthetic Semimetals with van der Waals Interfaces

Article Article scientifique Article Synthetic Semimetals with van der Waals Interfaces eng 2020 author Reddy Bojja Aditya 840218 author Ponomarev Evgeniy 819785 author Gutierrez Lezama Ignacio 681297 author Ubrig Nicolas 0000-0002-1966-4435 742176 author Barreteau Céline 817569 author Giannini Enrico 0000-0003-3536-4771 503364 author Morpurgo Alberto 666794 1322-1328 10.1021/acs.nanolett.9b04810 1530-6984 https://pubs.acs.org/doi/10.1021/acs.nanolett.9b04810 The assembly of suitably designed van der Waals (vdW) heterostructures represents a new approach to produce artificial systems with engineered electronic properties. Here, we apply this strategy to realize synthetic semimetals based on vdW interfaces formed by two different semiconductors. Guided by existing ab initio calculations, we select WSe2 and SnSe2 mono- and multilayers to assemble vdW interfaces and demonstrate the occurrence of semimetallicity by means of different transport experiments. Semimetallicity manifests itself in a finite minimum conductance upon sweeping the gate over a large range in ionic liquid gated devices, which also offer spectroscopic capabilities enabling the quantitative determination of the band overlap. The semimetallic state is additionally revealed in Hall effect measurements by the coexistence of electrons and holes, observed by either looking at the evolution of the Hall slope with sweeping the gate voltage or with lowering temperature. Finally, semimetallicity results in the low-temperature metallic conductivity of interfaces of two materials that are themselves insulating. These results demonstrate the possibility to implement a state of matter that had not yet been realized in vdW interfaces and represent a first step toward using these interfaces to engineer topological or excitonic insulating states. Van der Waals heterostructures Semimetal Band overlap Ionic liquid gating 2D materials Dewey 500.2 Swiss National Science Foundation Division II CH Autre Graphene Flagship 33 Département de physique de la matière quantique 131 35 Groupe de physique appliquée 135 false 678 Groupe Morpurgo Nano Letters 20 2 ea0b85bc-ceb6-4949-beb4-c206e8d4d108 Article (Accepted version) Public Manuscript_resub.pdf 2936108 application/pdf Restricted 2020-12-27 558cff2b-e1c7-4c86-a599-a8c894953b2b Supplemental data Public Supporting_information_resub.pdf 246112 application/pdf Restricted 2020-12-27 openAccess Faculté des sciences / Section de physique / Département de physique de la matière quantique Faculté des sciences / Section de physique / Groupe de physique appliquée

Title	Published in	Year	Views	Downloads

Spectroscopic investigation of ionic liquid gated van der Waals semiconductors and heterostructures		2021	553	480
Synthetic Semimetals with van der Waals Interfaces	Nano Letters	2020	556	539
Tunnelling spectroscopy of gate-induced superconductivity in MoS₂	Nature nanotechnology	2018	269	445
Electroluminescence from indirect band gap semiconductor ReS₂	2D materials	2016	289	0

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Reddy, Bojja Aditya