Revealing the two-dimensional electronic structure and anisotropic superconductivity in a natural van der Waals superlattice (PbSe)$_{1.14}$NbSe$_2$

Haoyuan Zhong; Hongyun Zhang; Haoxiong Zhang; Ting Bao; Kenan Zhang; Shengnan Xu; Laipeng Luo; Awabaikeli Rousuli; Wei Yao; Jonathan D. Denlinger; Yaobo Huang; Yang Wu; Yong Xu; Wenhui Duan; Shuyun Zhou

doi:10.1103/physrevmaterials.7.l041801

arXiv · 2304.12230

Revealing the two-dimensional electronic structure and anisotropic superconductivity in a natural van der Waals superlattice (PbSe)$_{1.14}$NbSe$_2$

Haoyuan Zhong·Hongyun Zhang·Haoxiong Zhang·Ting Bao·Kenan Zhang·Shengnan Xu·Laipeng Luo·Awabaikeli Rousuli·Wei Yao·Jonathan D. Denlinger·Yaobo Huang·Yang Wu·Yong Xu·Wenhui Duan·Shuyun Zhou

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Abstract

Van der Waals superlattices are important for tailoring the electronic structures and properties of layered materials. Here we report the superconducting properties and electronic structure of a natural van der Waals superlattice (PbSe)$_{1.14}$NbSe$_2$. Anisotropic superconductivity with a transition temperature $T_c$ = 5.6 $\pm$ 0.1 K, which is higher than monolayer NbSe$_2$, is revealed by transport measurements on high-quality samples. Angle-resolved photoemission spectroscopy (ARPES) measurements reveal the two-dimensional electronic structure and a charge transfer of 0.43 electrons per NbSe$_2$ unit cell from the blocking PbSe layer. In addition, polarization-dependent ARPES measurements reveal a significant circular dichroism with opposite contrast at K and K' valleys, suggesting a significant spin-orbital coupling and distinct orbital angular momentum. Our work suggests natural van der Waals superlattice as an effective pathway for achieving intriguing properties distinct from both the bulk and monolayer samples.

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Haoyuan Zhong, Hongyun Zhang, Haoxiong Zhang, Ting Bao, Kenan Zhang, Shengnan Xu, Laipeng Luo, Awabaikeli Rousuli, Wei Yao, Jonathan D. Denlinger, Yaobo Huang, Yang Wu, Yong Xu, Wenhui Duan, Shuyun Zhou. 2023-04-24. Revealing the two-dimensional electronic structure and anisotropic superconductivity in a natural van der Waals superlattice (PbSe)$_{1.14}$NbSe$_2$. https://doi.org/10.1103/physrevmaterials.7.l041801

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