Enhanced superconductivity with interlayer spacing dependent T _c in intercalated Weyl semimetal MoTe₂

Abstract

Manipulating the strength of the interlayer coupling is an effective strategy to induce intriguing properties in layered materials. Recently, enhanced superconductivity has been reported in Weyl semimetal MoTe2 and WTe2 via ionic liquid cation intercalation. However, how the superconductivity enhancement depends on the interlayer interaction still remains elusive. Here by inserting ionic liquid cations with different sizes into MoTe2 through this strategy, we are able to tune the interlayer spacing of the intercalated MoTe2 samples and reveal the dependence of superconducting transition temperature T c on the interlayer spacing. Our results show that T c increases with the interlayer spacing, suggesting that the weakened interlayer coupling plays an important role in the superconductivity. Interestingly, the intercalation induced superconductivity shows a high Ginzburg-Landau anisotropy, which suggests a quasi-two-dimensional nature of the superconductivity where the adjacent superconducting layers are coupled through Josephson tunneling.

Superconductivity in type II layered Weyl semi-metals

“…The effect of intercalation and density on superconductivity is studied. This explains both the remarkable features of T c observed [6] in MoTe 2 . The last section contains conclusions and discussion.…”

“…Typically, 15-25 iterations were required. We now concentrate on two puzzling experimental results of [6].…”

“…In figure 5, the critical temperatures for various values of density are plotted. The blue points are for the dielectric constant [6], ε = 16, describing the intercalated imidazole cations [C 2 MIm] [19]. The inter-layer distance was kept at d = 10.5 A.…”

“…The type II topology of the Fermi surface is achieved in particular in transition metal dichalcogenides [5]. Very recently, MoTe 2 layers intercalated by ionic liquid cations were studied [6].…”

Engineering Magnetism and Superconductivity in van der Waals Materials via Organic‐Ion Intercalation

“…Overall, other reports can be found in literature regarding the relation between charge carrier density, interlayer distance and the superconductive phenomenon. [26,40,[54][55][56][57] These works support the key role of organic compounds as tuning tools for layered compounds with superconducting properties, acting as cointercalating agents [58][59][60] or alone [44,53,61,62] .…”