Superconducting Cavity-Based Sensing of Band Gaps in 2D Materials

• DOI: 10.1021/acs.nanolett.3c04990
• Publication Date: 2024-02-23T17:14:35Z
• Authors: Krishnendu Maji; Joydip Sarkar; Supriya Mandal; Sriram H.; Mahesh Hingankar; Ayshi Mukherjee; Soumyajit Samal; Anirban Bhattacha...; Meghan P. Patankar; Kenji Watanabe; Takashi Taniguchi; Mandar M. Deshmukh
• Keywords: Superconductivity (cond-mat.supr-con); 0303 health sciences; 03 medical and health sciences; Condensed Matter - Mesoscale and Nanoscale Physics; Condensed Matter - Superconductivity; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); FOS: Physical sciences

The superconducting coplanar waveguide (SCPW) cavity plays an essential role in various areas like superconducting qubits, parametric amplifiers, radiation detectors, and studying magnon-photon and photon-phonon coupling. Despite its wide-ranging applications, the use of SCPW cavities to study various van der Waals 2D materials is relatively unexplored. The resonant modes of the SCPW cavity exquisitely sense the dielectric environment. In this work, we measure the charge compressibility of bilayer graphene coupled to a half-wavelength SCPW cavity. Our approach provides a means to detect subtle changes in the capacitance of the bilayer graphene heterostructure, which depends on the compressibility of bilayer graphene, manifesting as shifts in the resonant frequency of the cavity. This method holds promise for exploring a wide class of van der Waals 2D materials, including transition metal dichalcogenides (TMDs) and their moiré where DC transport measurement is challenging.