An on-chip compact Chebyshev filter for semiconductor quantum dots in cQED architecture

Abstract

Circuit quantum electrodynamics (cQED) architecture enables long-range qubit coupling and nondemolition readout, with a key requirement of a small resonator photon leakage rate, κ. Several types of low-pass on-chip LC filter designs have been proposed to mitigate κ. However, the non-flat frequency response in the passband introduces waveform distortion, which may degrade qubit performance. In this work, we develop an on-chip compact Chebyshev filter for semiconductor quantum dots in cQED architecture. It exhibits a flat passband up to a 2 GHz cutoff frequency with microwave attenuation <−30 dB at 7 GHz, without observing the sign of damping oscillations induced by waveform distortion. We also analyze the integration of the filter with the cQED architecture and demonstrate that microwave attenuation meets the need for integration. The developed Chebyshev filter paves the way for the precise control of semiconductor quantum dots in cQED architecture with a low photon leakage rate.