We report a super-insulating behavior, in a device having granular Pb film on back-gated few-layer MoS2, below an onset temperature same as the critical temperature TC≈7 K of bulk Pb. Below TC, the current-voltage characteristics exhibit a threshold voltage marking a crossover between the low-bias insulating and the high-bias normal-resistance states, consistent with the known super-insulating state behavior. A temperature dependent critical magnetic field is also found above which the insulating behavior is suppressed. The threshold voltage is found to vary with the gate-voltage but the critical field remains unchanged. With reducing temperature, the sample conductance saturates to a finite value, which depends on magnetic field and gate-voltage. This saturation behavior is found to be inconsistent with the charge-BKT and the thermal activation models but it can be fitted well to a combination of thermal activation and quantum fluctuations.
@article{arxiv.2505.17515,
title = {Superinsulating behavior in granular Pb film on gated few-layer MoS$_2$},
author = {Suraina Gupta and Santu Prasad Jana and Pawan Kumar Gupta and Anjan K. Gupta},
journal= {arXiv preprint arXiv:2505.17515},
year = {2025}
}