title: Enhanced superconductivity in atomically thin TaS2.
abstract: The ability to exfoliate layered materials down to the single layer limit has presented the opportunity to understand how a gradual reduction in dimensionality affects the properties of bulk materials. Here we use this top-down approach to address the problem of superconductivity in the two-dimensional limit. The transport properties of electronic devices based on 2H tantalum disulfide flakes of different thicknesses are presented. We observe that superconductivity persists down to the thinnest layer investigated (3.5 nm), and interestingly, we find a pronounced enhancement in the critical temperature from 0.5 to 2.2 K as the layers are thinned down. In addition, we propose a tight-binding model, which allows us to attribute this phenomenon to an enhancement of the effective electron-phonon coupling constant. This work provides evidence that reducing the dimensionality can strengthen superconductivity as opposed to the weakening effect that has been reported in other 2D materials so far.
authors.affiliation: Universidad de Valencia (ICMol), Catedrático José Beltrán Martínez n° 2, Paterna 46980, Spain.
authors.forename: Efrén
authors.initials: E
authors.lastname: Navarro-Moratalla
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft 2628 CJ, The Netherlands.
authors.forename: Joshua O
authors.initials: JO
authors.lastname: Island
authors.affiliation: Universidad de Valencia (ICMol), Catedrático José Beltrán Martínez n° 2, Paterna 46980, Spain.
authors.forename: Samuel
authors.initials: S
authors.lastname: Mañas-Valero
authors.affiliation: Universidad de Valencia (ICMol), Catedrático José Beltrán Martínez n° 2, Paterna 46980, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Pinilla-Cienfuegos
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft 2628 CJ, The Netherlands.
authors.forename: Andres
authors.initials: A
authors.lastname: Castellanos-Gomez
authors.affiliation: Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid 28049, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Quereda
authors.affiliation: Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid 28049, Spain.|Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid 28049, Spain.
authors.forename: Gabino
authors.initials: G
authors.lastname: Rubio-Bollinger
authors.affiliation: Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA- Nanociencia), Calle Farady 9, Cantoblanco, Madrid 28049, Spain.
authors.forename: Luca
authors.initials: L
authors.lastname: Chirolli
authors.affiliation: Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA- Nanociencia), Calle Farady 9, Cantoblanco, Madrid 28049, Spain.
authors.forename: Jose Angel
authors.initials: JA
authors.lastname: Silva-Guillén
authors.affiliation: Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid 28049, Spain.|Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid 28049, Spain.|Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA- Nanociencia), Calle Farady 9, Cantoblanco, Madrid 28049, Spain.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Agraït
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft 2628 CJ, The Netherlands.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Steele
authors.affiliation: Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA- Nanociencia), Calle Farady 9, Cantoblanco, Madrid 28049, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Guinea
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft 2628 CJ, The Netherlands.
authors.forename: Herre S J
authors.initials: HS
authors.lastname: van der Zant
authors.affiliation: Universidad de Valencia (ICMol), Catedrático José Beltrán Martínez n° 2, Paterna 46980, Spain.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Coronado