Piezoelectric effect at cryogenic temperatures: finding robust materials platforms for electromechanical quantum transduction

Quantum transduction, which refers to the conversion of a quantum signal from one form of energy to another form has been actively studied in the field of quantum information science and technology. Here, we survey a range of materials with various lattice constants, electronic band-gaps, and piezoelectric responses for cryogenic quantum transduction applications. We determine that thin-film titanates are promising materials for such applications. We present a systematic investigation of the physical and chemical characteristics of epitaxial barium titanate (BTO) thin film, a possible candidate for quantum transduction. Using pulsed laser deposition, we epitaxially grow barium titanate (BTO) on silicon and GaAs substrates using very thin buffer layers of YSZ, CeO2, STO and LaNiO3. The BTO heterostructures are characterized by X-ray diffraction, atomic force microscopy, and transmission electron microscopy. Furthermore, to evaluate potential phase change of the material at very low temperatures, we utilized cryogenic X-ray diffraction and electrical measurements including dielectric constant.