Combining molecular beam epitaxy and low-energy electron microscopy with in situ magnetic susceptibility measurements within an integrated ultrahigh vacuum system

Quantum two-dimensional materials, including ultrathin superconducting films, are of great current research interest. These films are typically fabricated under ultra-high vacuum (UHV) conditions and are sensitive to the environment—prone to oxidation and contamination when exposed to the atmosphere. This hampers the study of their intrinsic properties by standard ex situ techniques. Here, we present a variable-temperature mutual inductance probe system integrated under UHV with molecular beam epitaxy (MBE) synthesis and low-energy electron microscopy, enabling nondestructive in situ characterization of superconducting thin films. The system employs a reflection-type configuration and reaches a low temperature (∼4 K) using a high-cooling-power, vibration-isolated cryocooler. We demonstrate the system performance by measuring the superconducting critical temperature in a copper-oxide thin film.