Parametric amplification of multimode high-kinetic inductance cavity

Abstract Parametric amplifiers have become significant components in qubit readout within circuit quantum electrodynamics. Devices based on high-kinetic inductance (HKI) material can provide an avenue to achieve the considerable gain of parametric amplification. In this work, we develop a parametric amplifier using a multimode HKI coplanar waveguide cavity. We explore two pumping schemes, achieving significant gains for multiple modes in both the monochromatic and bichromatic pump schemes. We first measure parametric amplification in the monochromatic pump scheme, achieving over <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>10</mml:mn> <mml:mtext> </mml:mtext> <mml:mrow> <mml:mrow> <mml:mi>dB</mml:mi> </mml:mrow> </mml:mrow> </mml:mrow> </mml:math> gain in all modes. In the bichromatic pump scheme, two distinct gain regions emerge in the spectra, accompanied by a triangle-like pattern. Moreover, the bichromatic pump scheme yields a higher gain value than the monochromatic pump scheme, with the maximum gain exceeding <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>27</mml:mn> <mml:mtext> </mml:mtext> <mml:mrow> <mml:mrow> <mml:mi>dB</mml:mi> </mml:mrow> </mml:mrow> </mml:mrow> </mml:math> . This parametric amplifier holds potential applications, such as frequency-division multiplexing readout, which is beneficial for scaling up qubits in quantum computing.