Tang Fangdong, Wang Peipei, Wang Qixing, Gan Yuan, Lyu Jian, Mi Xinrun, He Mingquan, Zhang Liyuan, Smet Jurgen H
Max Planck Institute for Solid State Research, Stuttgart 70569, Germany.
Department of Physics and Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Nano Lett. 2023 Aug 23;23(16):7516-7523. doi: 10.1021/acs.nanolett.3c02033. Epub 2023 Aug 4.
Gate tunable two-dimensional (2D) superconductors offer significant advantages in studying superconducting phase transitions. Here, we address superconductivity in exfoliated 1T'-MoTe monolayers with an intrinsic band gap of ∼7.3 meV using field effect doping. Despite large differences in the dispersion of the conduction and valence bands, superconductivity can be achieved easily for both electrons and holes. The onset of superconductivity occurs near 7-8 K for both charge carrier types. This temperature is much higher than that in bulk samples. Also the in-plane upper critical field is strongly enhanced and exceeds the BCS Pauli limit in both cases. Gap information is extracted using point-contact spectroscopy. The gap ratio exceeds multiple times the value expected for BCS weak-coupling. All of these observations suggest a strong enhancement of the pairing interaction.
栅极可调谐二维（2D）超导体在研究超导相变方面具有显著优势。在此，我们通过场效应掺杂研究了具有约7.3 meV本征带隙的剥离1T'-MoTe单层中的超导性。尽管导带和价带的色散存在很大差异，但电子和空穴都能很容易地实现超导。两种载流子类型的超导起始温度都在7 - 8 K附近。这个温度远高于体材料样品中的温度。而且面内上临界场也显著增强，在两种情况下都超过了BCS泡利极限。使用点接触光谱法提取能隙信息。能隙比超过了BCS弱耦合预期值的数倍。所有这些观察结果都表明配对相互作用得到了显著增强。
