title: Metal to Insulator Quantum-Phase Transition in Few-Layered ReS₂.
abstract: In ReS2, a layer-independent direct band gap of 1.5 eV implies a potential for its use in optoelectronic applications. ReS2 crystallizes in the 1T'-structure, which leads to anisotropic physical properties and whose concomitant electronic structure might host a nontrivial topology. Here, we report an overall evaluation of the anisotropic Raman response and the transport properties of few-layered ReS2 field-effect transistors. We find that ReS2 exfoliated on SiO2 behaves as an n-type semiconductor with an intrinsic carrier mobility surpassing μ(i) ∼ 30 cm(2)/(V s) at T = 300 K, which increases up to ∼350 cm(2)/(V s) at 2 K. Semiconducting behavior is observed at low electron densities n, but at high values of n the resistivity decreases by a factor of >7 upon cooling to 2 K and displays a metallic T(2)-dependence. This suggests that the band structure of 1T'-ReS2 is quite susceptible to an electric field applied perpendicularly to the layers. The electric-field induced metallic state observed in transition metal dichalcogenides was recently claimed to result from a percolation type of transition. Instead, through a scaling analysis of the conductivity as a function of T and n, we find that the metallic state of ReS2 results from a second-order metal-to-insulator transition driven by electronic correlations. This gate-induced metallic state offers an alternative to phase engineering for producing ohmic contacts and metallic interconnects in devices based on transition metal dichalcogenides.
authors.affiliation: National High Magnetic Field Lab, Florida State University , 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States.
authors.forename: Nihar R
authors.initials: NR
authors.lastname: Pradhan
authors.affiliation: Department of Physics and Center for 2-Dimensional and Layered Materials, Pennsylvania State University , University Park, State College, Pennsylvania 16802, United States.|Computational & Information Sciences Directorate, U.S. Army Research Laboratory , Adelphi, Maryland 20783, United States.|Sensor & Electron Devices Directorate, U.S. Army Research Laboratory , Adelphi, Maryland 20783, United States.
authors.forename: Amber
authors.initials: A
authors.lastname: McCreary
authors.affiliation: National High Magnetic Field Lab, Florida State University , 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States.|Department of Physics, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rhodes
authors.affiliation: National High Magnetic Field Lab, Florida State University , 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States.|Department of Physics, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Zhengguang
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Department of Physics and Center for 2-Dimensional and Layered Materials, Pennsylvania State University , University Park, State College, Pennsylvania 16802, United States.
authors.forename: Simin
authors.initials: S
authors.lastname: Feng
authors.affiliation: National High Magnetic Field Lab, Florida State University , 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States.|Department of Physics, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Efstratios
authors.initials: E
authors.lastname: Manousakis
authors.affiliation: National High Magnetic Field Lab, Florida State University , 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Smirnov
authors.affiliation: Computational & Information Sciences Directorate, U.S. Army Research Laboratory , Adelphi, Maryland 20783, United States.
authors.forename: Raju
authors.initials: R
authors.lastname: Namburu
authors.affiliation: Sensor & Electron Devices Directorate, U.S. Army Research Laboratory , Adelphi, Maryland 20783, United States.
authors.forename: Madan
authors.initials: M
authors.lastname: Dubey
authors.affiliation: Engineering Physics Division, Physics Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: Angela R Hight
authors.initials: AR
authors.lastname: Walker
authors.affiliation: Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.
authors.forename: Humberto
authors.initials: H
authors.lastname: Terrones
authors.affiliation: Department of Physics and Center for 2-Dimensional and Layered Materials, Pennsylvania State University , University Park, State College, Pennsylvania 16802, United States.|Department of Chemistry and Department of Materials Science and Engineering, The Pennsylvania State University , University Park, State College, Pennsylvania 16802, United States.|Carbon Institute of Science and Technology, Shinshu University , Wakasato 4-17-1, Nagano-city 380-8553, Japan.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Terrones
authors.affiliation: National High Magnetic Field Lab, Florida State University , 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States.|Department of Physics, Florida State University , Tallahassee, Florida 32306, United States.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Dobrosavljevic
authors.affiliation: National High Magnetic Field Lab, Florida State University , 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States.
authors.forename: Luis
authors.initials: L
authors.lastname: Balicas
keywords: Raman scattering; Transition metal dichalcogenides; field-effect mobilities; field-effect transistor; metal−insulator transition; rhenium disulfide