Combining an in situ device fabrication and six-probe electrical transport measurement system with low-energy electron microscopy.

The article focuses on the development and demonstration of an integrated ultrahigh vacuum (UHV) experimental system combining molecular beam epitaxy (MBE) synthesis, low-energy electron microscopy/diffraction (LEEM/LEED), and an in situ six-probe electrical transport measurement apparatus. This setup enables the synthesis, structural characterization, electrode fabrication, and electrical resistance measurements of atmosphere-sensitive two-dimensional (2D) quantum materials—such as borophene and other "X-enes"—without exposure to ambient conditions, preserving their intrinsic properties. The six-probe system supports both macro- and micro-scale resistance measurements across a wide temperature range (5 K to 400 K) and allows detection of anisotropic resistivity. Experimental validation includes resistance measurements on various materials, including SrTiO3, YBa2Cu3O7−δ, La1.84Sr0.16Cu2O4, and Si(111) surfaces with different reconstructions, demonstrating phenomena such as metal–insulator transitions. This integrated platform represents a significant advance for studying the surface structure and transport properties of reactive 2D quantum materials under controlled conditions.