Enhanced superconductivity in atomically thin TaS 2

Enhanced superconductivity in atomically thin TaS 2

Navarro-Moratalla, Efrén (Universidad de Valencia (ICMol))
Island, J.O. (TU Delft QN/van der Zant Lab)
Manãs-Valero, Samuel (Universidad de Valencia (ICMol))
Pinilla-Cienfuegos, Elena (Universidad de Valencia (ICMol))
Castellanos Gomez, A. (TU Delft QN/Mol. Electronics & Devices)
Quereda, Jorge (Universidad Autónoma de Madrid)
Rubio-Bollinger, Gabino (Universidad Autónoma de Madrid)
Chirolli, Luca (Instituto Madrilenõ de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia))
Silva-Guillén, Jose Angel (Instituto Madrilenõ de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia))
Agraït, Nicolás (Instituto Madrilenõ de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia); Universidad Autónoma de Madrid)
Steele, G.A. (TU Delft QN/Steele Lab)
Guinea, Francisco (Instituto Madrilenõ de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia))
van der Zant, H.S.J. (TU Delft QN/van der Zant Lab; Kavli institute of nanoscience Delft)
Coronado, Eugenio (Universidad de Valencia (ICMol))

2016-03-17

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.

http://resolver.tudelft.nl/uuid:7b5aa421-5f02-4402-a7f1-580b843ed865

https://doi.org/10.1038/ncomms11043

2041-1723

Nature Communications, 7, 1-7

Institutional Repository

journal article

© 2016 Efrén Navarro-Moratalla, J.O. Island, Samuel Manãs-Valero, Elena Pinilla-Cienfuegos, A. Castellanos Gomez, Jorge Quereda, Gabino Rubio-Bollinger, Luca Chirolli, Jose Angel Silva-Guillén, Nicolás Agraït, G.A. Steele, Francisco Guinea, H.S.J. van der Zant, Eugenio Coronado