Superconductivity of a micron-sized hydride under extreme pressure measured between metal probes could be considered as a macroscopic “quantum tunnelling” phenomenon through metal-hydride-metal. The energy barrier height of hydride is regulated by pressure. The hydride barrier width between tips of the metal probes should be minimized to avoid exponential decay in electron tunnelling. There is also a thickness effect as thinner samples around 1 micron are favoured for achieving higher superconductive temperatures. Based on the consideration of quantum tunnelling, reduction in both barrier width and sample thickness is recommended for the realization of room temperature superconductivity from the current experimentally-confirmed 260 K. Latest experimental results reported in the literature on room temperature superconductivity of super-hydrides will be discussed and compared with the proposed size effect approach.

Keywords: Quantum Tunnelling; Room-Temperature Superconductivity; Size Effects