The development of reliable superconducting circuits is key to the promise of quantum computing. One area of unreliability is the energy loss from dielectric material in the circuits. Various materials have been tried to minimize or eliminate dielectric loss, starting with silicon and variants. Navy researchers have identified hydrogen-free amorphous silicon (a-Si) laid down by electron beam deposition to be an ideal dielectric for use in quantum computer circuits. This high-quality insulating dielectric material is free from two-level tunneling systems (localized excitations due to defects in the disordered material). The material effectively separates two superconducting layers without producing dielectric losses or decoherence (wave interference causing loss of information from the system).
A continuation in part of this patent is being prosecuted as US application number 20170069819.
- a-Si has a high mass density of at least 90 percent of the density of crystalline counterparts
- Patent is not restricted to a-Si thin films, but also includes high-density amorphous germanium (a-Ge) or amorphous carbon (a-C), or a compound or alloy film formed from at least two elements (for example, from two or more of silicon, germanium, carbon, nitrogen, phosphorus, arsenic, boron, aluminum, gallium, or oxygen)
- Deposition can be by electron beam (e-beam) evaporation or any other suitable deposition technique, such as sputtering, chemical vapor deposition, or pulsed laser deposition
- US patent 9,530,535 available for license
- Potential for collaboration with Navy researchers