Beyond Conventional Charge Density Wave for Strongly Enhanced 2D Superconductivity in 1H-TaS2 Superlattices

Zejun Li; Pin Lyu; Zhaolong Chen; Dandan Guan; Shuang Yu; Jinpei Zhao; Pengru Huang; Xin Zhou; Zhizhan Qiu; Hanyan Fang; Makoto Hashimoto; Donghui Lu; Fei Song; Kian Ping Loh; Yi Zheng; Zhi-Xun Shen; Kostya S Novoselov; Jiong Lu

doi:10.1002/adma.202312341

Beyond Conventional Charge Density Wave for Strongly Enhanced 2D Superconductivity in 1H-TaS₂ Superlattices

Adv Mater. 2024 Apr 3:e2312341. doi: 10.1002/adma.202312341. Online ahead of print.

Authors

Zejun Li^{1

2

3}, Pin Lyu², Zhaolong Chen^{4

5}, Dandan Guan⁶, Shuang Yu⁷, Jinpei Zhao⁴, Pengru Huang^{4

8}, Xin Zhou², Zhizhan Qiu⁴, Hanyan Fang², Makoto Hashimoto⁹, Donghui Lu⁹, Fei Song¹⁰, Kian Ping Loh², Yi Zheng⁷, Zhi-Xun Shen^{9

11}, Kostya S Novoselov⁴, Jiong Lu^{2

4}

Affiliations

¹ Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing, 211189, China.
² Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore.
³ Purple Mountain Laboratories, Nanjing, 211111, China.
⁴ Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore.
⁵ School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
⁶ Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.
⁷ Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, 310027, China.
⁸ Guangxi Key Laboratory of Information Materials, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin, 541004, China.
⁹ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.
¹⁰ Shanghai Synchrotron Radiation Faciality, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China.
¹¹ Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, Stanford, CA, 94305, USA.

PMID: 38567889
DOI: 10.1002/adma.202312341

Abstract

Noncentrosymmetric transition metal dichalcogenide (TMD) monolayers offer a fertile platform for exploring unconventional Ising superconductivity (SC) and charge density waves (CDWs). However, the vulnerability of isolated monolayers to structural disorder and environmental oxidation often degrade their electronic coherence. Herein, an alternative approach is reported for fabricating stable and intrinsic monolayers of 1H-TaS₂ sandwiched between SnS blocks in a (SnS)_1.15TaS₂ van der Waals (vdW) superlattice. The SnS block layers not only decouple individual 1H-TaS₂ sublayers to endow them with monolayer-like electronic characteristics, but also protect the 1H-TaS₂ layers from electronic degradation. The results reveal the characteristic 3 × 3 CDW order in 1H-TaS₂ sublayers associated with electronic rearrangement in the low-lying sulfur p band, which uncovers a previously undiscovered CDW mechanism rather than the conventional Fermi surface-related framework. Additionally, the (SnS)_1.15TaS₂ superlattice exhibits a strongly enhanced Ising-like SC with a layer-independent T_c of ≈3.0 K, comparable to that of the isolated monolayer 1H-TaS₂ sample, presumably attributed to their monolayer-like characteristics and retained Fermi states. These results provide new insights into the long-debated CDW order and enhanced SC of monolayer 1H-TaS₂, establishing bulk vdW superlattices as promising platforms for investigating exotic collective quantum phases in the 2D limit.

Keywords: 2D superconductivity; 2D van der Waals superlattices; charge density wave; electronic rearrangement; monolayer‐like electronic characteristics.

Abstract

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