Enhancement of superconductivity in organic-inorganic hybrid topological materials

Abstract

Inducing or enhancing superconductivity in topological materials is an important route toward topological superconductivity. Reducing the thickness of transition metal dichalcogenides (e.g. WTe 2 and MoTe 2 ) has provided an important pathway to engineer superconductivity in topological matters; for instance, emergent superconductivity with T c ∼ 0.82 K was observed in monolayer WTe 2 1, 2 which also hosts intriguing quantum spin Hall effect 3 , although the bulk crystal is nonsuperconducting. However, such monolayer sample is difficult to obtain, unstable in air, and with extremely low T c , which could pose a grand challenge for practical applications. Here we report an experimentally convenient approach to control the interlayer coupling to achieve tailored topological properties, enhanced superconductiv-1 arXiv:1911.02228v1 [cond-mat.mtrl-sci]

Intercalated phases of transition metal dichalcogenides

“…The absence of phase change and the presence of positive magnetoresistance (MR; Figure 7E) indicate that the topology of WTe 2 persists after intercalation, suggesting K x WTe 2 could be a topological superconductor. 124 Zhang et al 36 intercalated organic cations in WTe 2 and MoTe 2 with an electrochemical reaction method using ionic liquids [C n MIm] + [TFSI] + (1-alkyl-3-methylimidazoliumbis(trifluoromethylsulfonyl)imide) as reacting agent. 36 The interlayer coupling of the WTe 2 and MoTe 2 crystals are weakened by the organic intercalants, leading to an enhanced SC critical temperature at 7.0 K for intercalated MoTe 2 , and 2.3 K for intercalated WTe 2 .…”

“…124 Zhang et al 36 intercalated organic cations in WTe 2 and MoTe 2 with an electrochemical reaction method using ionic liquids [C n MIm] + [TFSI] + (1-alkyl-3-methylimidazoliumbis(trifluoromethylsulfonyl)imide) as reacting agent. 36 The interlayer coupling of the WTe 2 and MoTe 2 crystals are weakened by the organic intercalants, leading to an enhanced SC critical temperature at 7.0 K for intercalated MoTe 2 , and 2.3 K for intercalated WTe 2 . Therefore, organic cation intercalation can control the dimensionality of layered materials.…”

“…32 In 1986, the first monolayer MoS 2 suspension was reported through intercalation with lithium followed by reaction with water. 33 Intercalation modifies the properties of TMD by a myriad of effects, including charge doping, [34][35][36] expansion of c axis lattice constants, [37][38][39][40] orbital hybridization, [41][42][43] and phonon scattering. 37,44,45 A wide range of properties could be promoted or tuned, from electrical conductivity, 46,47 optical modes, 48,49 magnetic order, 43,50 thermoelectricity, 45,51 catalytic activities, 52,53 to energy storage and conversion performances.…”

Boosting superconductivity in organic-inorganic superlattices

“…1a). A research team co-leaded by Prof. Zhou and Prof. Yu has adopted the intercalation method to manipulate the interlayer coupling in bulk TMD materials and studied the associated superconducting behavior in these elaborately tailored systems [8].…”

“…(a) Intercalation of various host materials and intercalants [6]. (b) Schematic for the emergence of superconducting weak topological insulators from type II Weyl fermion in bulk MoTe 2 and WTe 2 through ion intercalation [8].…”