Broadband Microwave Measurement Platform for Exploring Strongly Correlated Phases in TMD Moiré Heterostructures

Moiré transition metal dichalcogenide (TMD) heterostructures provide a highly tunable platform for studying strongly correlated electronic states, yet their high frequency electrodynamics remains largely unexplored. We present a cryogenic measurement platform designed to probe the GHz frequency transmission of gate tunable TMD-based devices in a dilution refrigerator. Our approach integrates a gapped coplanar waveguide with a graphite gate, enabling simultaneous DC transport and microwave S-parameter measurements down to 10 mK. We have previously demonstrated the ability to get absolute measurement of complex conductivity in contrast to the established µ-wave scanned probe measurement.

This platform is engineered for studies of moiré WS₂ / WSe₂ heterobilayers, where Mott insulating behavior is expected, and MoSe₂ devices which host Wigner crystal phases at low carrier density. By sweeping gate voltage and probing a broadband microwave transmission, our setup aims to access the electrodynamic response associated with correlated insulating states and Wigner crystal dynamics. To date, we have experimentally observed transmission in WS₂ / WSe₂ bilayers which is strongly dependent on the controlled gate voltage.