Three-wave-mixing element with quantum paraelectric materials
Phys. Rev. Applied 25, 024091 – Published 27 February, 2026
DOI: https://doi.org/10.1103/wbdc-p8pq
Abstract
At cryogenic temperatures and microwave frequencies, the perovskite crystals strontium titanate (STO) and potassium tantalate (KTO) have large, tunable permittivity arising from a quantum paraelectric phase. As such, these materials hold promise as a platform to realize compact, variable capacitance elements for use as three-wave-mixing elements in quantum devices. From modulating this capacitance within a resonant circuit, we propose the development of a quantum “paraelectric nonlinear dielectric amplifier” (PANDA). We calculate that a PANDA made from a nanofabricated parallel plate capacitor and realistic design constraints can demonstrate a three-wave-mixing strength of order MHz, in comparison to an effective Kerr strength of sub-Hz. This suggests excellent performance as a degenerate parametric amplifier, with high compression power in analogy to superconducting parametric amplifiers based on kinetic inductance. Beyond parametric amplifiers, we predict that compact, tunable capacitors based on STO, KTO, and related materials can enable a wide class of cryogenic quantum circuits including alternative filters, switches, circulators, and qubits.
