Tunneling spectroscopy of field-induced superconductivity in molybdenum disulfide using top metal contacts

Abstract

Field-induced superconductivity has been observed on the surfaces of various materials; however, the underlying mechanism of this two-dimensional superconductivity remains elusive. While tunneling spectroscopy measurements provide valuable insights into the microscopic nature of the superconducting state, there is a scarcity of tunneling spectroscopy measurements specifically focused on field-induced superconductivity when compared to transport measurements. In this study, we present a novel approach for tunneling spectroscopy using top metal contacts on field-induced superconducting MoS2. Our experimental findings, including the energy gap values, are consistent with those of a previous study conducted using a different device configuration. The observed energy-dependent density of states cannot be explained by the conventional BCS mechanism. We address the impact of inhomogeneity within the superconducting phase and discuss potential methods for its suppression. The proposed tunneling spectroscopy technique offers simplicity and ease of implementation, making it applicable for investigating other two-dimensional superconducting systems.