Liquid-gated interface superconductivity on an atomically flat film

Abstract

Liquid/solid interfaces are attracting growing interest not only for applications in catalytic activities and energy storage, but also for their new electronic functions in electric double-layer transistors (EDLTs) exemplified by high-performance organic electronics, field-induced electronic phase transitions, as well as superconductivity in SrTiO(3) (ref. 12). Broadening EDLTs to induce superconductivity within other materials is highly demanded for enriching the materials science of superconductors. However, it is severely hampered by inadequate choice of materials and processing techniques. Here we introduce an easy method using ionic liquids as gate dielectrics, mechanical micro-cleavage techniques for surface preparation, and report the observation of field-induced superconductivity showing a transition temperature T(c)=15.2 K on an atomically flat film of layered nitride compound, ZrNCl. The present result reveals that the EDLT is an extremely versatile tool to induce electronic phase transitions by electrostatic charge accumulation and provides new routes in the search for superconductors beyond those synthesized by traditional chemical methods.

Hopping transport and the Hall effect near the insulator–metal transition in electrochemically gated poly(3-hexylthiophene) transistors

“…In essence, the device is a four-terminal bottom-contacted van der Pauw geometry P3HT thin film transistor, gated electrochemically using an ion gel based on an ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoro-methylsulfonyl) imide ((EMIM)(TFSI))) and a triblock copolymer (poly(styrene-b-methylmethacrylate-b-styrene; PS-PMMA-PS)) [19][20][21] . Such ionic liquids and gels have been used recently to electrostatically induce two-dimensional charge densities B10 14 cm À 2 in a variety of materials (for example, refs [22][23][24][25]. In the case of semi-crystalline semiconducting polymers such as P3HT, the open structure results in deep penetration of the dopant ions, providing uniform 3D electrochemical doping (Fig.…”

Interface superconductivity

“…ZrNCl [84] allowing large changes in the superconducting transition temperatures to be achieved. Further work allowed superconductivity in the incipient ferroelectric KTaO 3 to be induced [10].…”

Superconducting Transition Temperature Modulation in NbN via EDL Gating

“…Indeed, the EDL that builds up at the interface between the active channel and a polymer electrolyte solution (or an ionic liquid) acts as an effective nanoscale capacitor with extremely high capacitance [1]. In the field of superconductivity, EDL…”