Gated Tuned Superconductivity and Phonon Softening in Mono- and Bilayer MoS${}_2$

Abstract

Superconductors at the atomic two-dimensional (2D) limit are the focus of an enduring fascination in the condensed matter community. This is because, with reduced dimensions, the effects of disorders, fluctuations, and correlations in superconductors become particularly prominent at the atomic 2D limit; thus such superconductors provide opportunities to tackle tough theoretical and experimental challenges. Here, based on the observation of ultrathin 2D superconductivity in mono- and bilayer molybdenum disulfide (MoS${}_2$) with electric-double-layer (EDL) gating, we found that the critical sheet carrier density required to achieve superconductivity in a monolayer MoS${}_2$ flake can be as low as 0.55*10${}^{14}$cm${}^{-2}$, which is much lower than those values in the bilayer and thicker cases in previous report and also our own observations. Further comparison of the phonon dispersion obtained by ab initio calculations indicated that the phonon softening of the acoustic modes around the M point plays a key role in the gate-induced superconductivity within the Bardeen-Cooper Schrieffer (BCS) theory framework. This result might help enrich the understanding of 2D superconductivity with EDL gating.

References in corpus (3)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Possible Topological Superconducting Phases of MoS${}_2$
• Electrostatically Induced Superconductivity at the Surface of WS${}_2$

Cited by in corpus (13)

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• Prediction of phonon-mediated superconductivity with high critical temperature in the two-dimensional topological semimetal W2N3
• The soft-mode phonons mediated unconventional superconductivity in monolayer 1T'-WTe2
• Dynamical renormalization of electron-phonon coupling in conventional superconductors
• Metal-insulator transition in monolayer MoS${}_2$ via contactless chemical doping
• Emergence of large non-adiabatic effects induced by the electron-phonon interaction on the complex vibrational quasi-particle spectrum of the doped monolayer MoS${}_2$
• Ultrafast charge dynamics and photoluminescence in bilayer MoS2
• Competition between phonon mediated superconductivity and carriers localization in field-effect doped molybdenum dichalcogenides
• Anomalous metallic phase in molybdenum disulphide induced via gate-driven organic ion intercalation
• Strong band-filling-dependence of the scattering lifetime in gated MoS2 nanolayers induced by the opening of intervalley scattering channels
• Geometric inhibition of superflow in single-layer graphene suggests a staggered-flux superconductivity in bilayer and trilayer graphene
• Observation of surface superconductivity in bulk polycrystalline MoS2 induced by electric double-layer doping
• Third-order nonlinear transport in a percolative two-dimensional superconductor