Interferometric Purcell suppression of spontaneous emission in a superconducting qubit (2405.10107v2)
Abstract: In superconducting qubits, suppression of spontaneous emission is essential to achieve fast dispersive measurement and reset without sacrificing qubit lifetime. We show that resonator-mediated decay of the qubit mode to the feedline can be suppressed using destructive interference, where the readout resonator is coupled to the feedline at two points. This "interferometric Purcell filter" does not require dedicated filter components or impedance mismatch in the feedline, making it suitable for applications such as all-pass readout. We design and fabricate a device with the proposed scheme and demonstrate suppression of resonator-mediated decay that exceeds 2 orders of magnitude over a bandwidth of 400 MHz for a resonator linewidth of 13.8 MHz.
- E. Purcell, Proceedings of the American Physical Society, Physical Review 69, 674 (1946).
- E. A. Sete, J. M. Martinis, and A. N. Korotkov, Quantum theory of a bandpass Purcell filter for qubit readout, Physical Review A 92, 012325 (2015).
- L. C. G. Govia and A. A. Clerk, Enhanced qubit readout using locally generated squeezing and inbuilt Purcell-decay suppression, New Journal of Physics 19, 023044 (2017).
- A. F. Kockum, G. Johansson, and F. Nori, Decoherence-Free Interaction between Giant Atoms in Waveguide Quantum Electrodynamics, Physical Review Letters 120, 140404 (2018).
- D. Esteve, M. H. Devoret, and J. M. Martinis, Effect of an arbitrary dissipative circuit on the quantum energy levels and tunneling of a Josephson junction, Physical Review B 34, 158 (1986).
- D. M. Pozar, Microwave Engineering, 4th ed. (Wiley, Hoboken, NJ, 2012).