Sol-gel deposited RuO2 film on lead-bismuth-silicate glass for cryogenic quantum computing

Abstract

Microchannel plate (MCP) is an important potential readout device for cryogenic quantum computing, especially for the quantum computation based on floating electrons of liquid helium surface. The signal readout time is a primary property of quantum computing, which is grounded in and proportional to the bulk resistance of the MCP multiplier. Notwithstanding, the bulk resistance of the MCP multiplier became giant at cryogenic temperature for the property of huge negative temperature coefficient of resistance, almost 105 Gohm at 20K~30K, resulting in a readout time of 10-2-1s at cryogenic temperature. That was one of the major bottlenecks for the cryogenic quantum computing application of MCPs. In this paper, ruthenium oxide films were sol-gel deposited onto the lead-bismuth-silicate glass, one kind of the base material for MCPs, produced by the Research and Development Center of Microchannel Plate, China Building Materials Academy. Surface topographic properties of the film were investigated with a laser scanning confocal microscope (LSCM). The hybrid bulk-resistance of RuO2 film deposited glass was measured in a modified Vacuum Photoelectron Imaging Test Facility (VPIT). It indicated that the sol-gel deposited RuO2 film could decrease the bulk resistance of hydrogen-reduced lead-bismuth-silicate glass and effectively mitigate its giant thermal resistance. This research can give a significant reference for developing MCP detectors in cryogenic quantum computing applications.