Method for producing transmon qubit and lithium niobate resonator on the same substrate

A non-transitory computer readable storage medium storing a plurality of instructions which, when executed, generate a device according to steps, comprising:

• forming, from a layer of protonatable piezoelectric material positioned on a silicon substrate, a structure of protonatable piezoelectric material on the silicon substrate, wherein the structure of the protonatable piezoelectric material is formed by defining and removing portions of the layer of the protonatable piezoelectric material on the silicon substrate through a combination of:
• (a) application of a proton exchange treatment to the layer of protonatable piezoelectric material with a patterned mask to cause proton exchange in exposed portions of the protonatable piezoelectric material followed by wet etching the layer of protonatable piezoelectric material to remove proton exchanged portions of the protonatable piezoelectric material;
• and
• (b) removing portions of the layer of protonatable piezoelectric material using a dry etch process;
• forming an electrode layer on the silicon substrate;
• forming a nonlinear element on the electrode layer at a position spaced apart from the structure of the protonatable piezoelectric material;
• and
• removing at least some of the silicon substrate under the structure of protonatable piezoelectric material to form a void below the structure of protonatable piezoelectric material.