Author(s): Zhang, HX (Zhang, Haoxiong); Rousuli, A (Rousuli, Awabaikeli); Zhang, KN (Zhang, Kenan); Luo, LP (Luo, Laipeng); Guo, CG (Guo, Chenguang); Cong, X (Cong, Xin); Lin, ZZ (Lin, Zuzhang); Bao, CH (Bao, Changhua); Zhang, HY (Zhang, Hongyun); Xu, SN (Xu, Shengnan); Feng, RF (Feng, Runfa); Shen, SC (Shen, Shengchun); Zhao, K (Zhao, Kun); Yao, W (Yao, Wei); Wu, Y (Wu, Yang); Ji, SH (Ji, Shuaihua); Chen, X (Chen, Xi); Tan, PH (Tan, Pingheng); Xue, QK (Xue, Qi-Kun); Xu, Y (Xu, Yong); Duan, WH (Duan, Wenhui); Yu, P (Yu, Pu); Zhou, SY (Zhou, Shuyun)

Source: NATURE PHYSICS DOI: 10.1038/s41567-022-01778-7 Early Access Date: OCT 2022

Abstract: Reducing the dimensionality of layered materials can result in properties distinct from their bulk crystals(1-3). However, the emergent properties in atomically thin samples, in particular in metallic monolayer flakes, are often obtained at the expense of other important properties. For example, while Ising superconductivity-where the pairing of electrons with opposite out-of-plane spins from K and K' valleys leads to an in-plane upper critical field exceeding the Paul' limit-does not occur in bulk NbSe2, it was observed in two-dimensional monolayer flakes(4). However, the critical temperature was reduced as compared to bulk crystals(4-13). Here we take a different route to control the superconducting properties of NbSe2 by intercalating bulk crystals with cations from ionic liquids. This produces Ising superconductivity with a similar critical temperature to the non-intercalated bulk and is more stable than in a monolayer flake. Our angle-resolved photoemission spectroscopy measurements reveal the effectively two-dimensional electronic structure, and a comparison of the experimental electronic structures between intercalated bulk NbSe2 and monolayer NbSe2 film reveals that the intercalant induces electron doping. This suggests ionic liquid cation intercalation is an effective technique for controlling both the dimensionality and the carrier concentration, allowing tailored properties exceeding both bulk crystals and monolayer samples.

Accession Number: WOS:000867606500001

Author Identifiers:

Author        Web of Science ResearcherID        ORCID Number

TAN, Ping-Heng         D-1137-2009         0000-0001-6575-1516

ISSN: 1745-2473

eISSN: 1745-2481

Full Text: https://www.nature.com/articles/s41567-022-01778-7