Phonon-protected superconducting qubits

Mutasem Odeh

EECS Department, University of California, Berkeley

Technical Report No. UCB/EECS-2023-269

December 14, 2023

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http://www2.eecs.berkeley.edu/Pubs/TechRpts/2023/Archive/EECS-2023-269.pdf

The overhead to construct a logical qubit from physical qubits rapidly increases with the de- coherence rate. Current superconducting qubits reduce dissipation due to two-level systems (TLSs) by using large device footprints. However, this approach provides partial protection, and results in a trade-off between qubit footprint and dissipation. This work introduces a new platform using phononics to engineer superconducting qubit-TLS interactions. We realize a superconducting qubit on a phononic bandgap metamaterial that suppresses TLS- mediated phonon emission. We use the qubit to probe its thermalization dynamics with the phonon-engineered TLS bath. Inside the phononic bandgap, we observe the emergence of non-Markovian qubit dynamics due to the Purcell-engineered TLS lifetime of 34 μs. We discuss the implications of these observations for extending qubit relaxation times through simultaneous phonon protection and miniaturization.

Advisors: Alp Sipahigil

BibTeX citation:

@phdthesis{Odeh:EECS-2023-269,
    Author= {Odeh, Mutasem},
    Title= {Phonon-protected superconducting qubits},
    School= {EECS Department, University of California, Berkeley},
    Year= {2023},
    Month= {Dec},
    Url= {http://www2.eecs.berkeley.edu/Pubs/TechRpts/2023/EECS-2023-269.html},
    Number= {UCB/EECS-2023-269},
    Abstract= {The overhead to construct a logical qubit from physical qubits rapidly increases with the de- coherence rate. Current superconducting qubits reduce dissipation due to two-level systems (TLSs) by using large device footprints. However, this approach provides partial protection, and results in a trade-off between qubit footprint and dissipation. This work introduces a new platform using phononics to engineer superconducting qubit-TLS interactions. We realize a superconducting qubit on a phononic bandgap metamaterial that suppresses TLS- mediated phonon emission. We use the qubit to probe its thermalization dynamics with the phonon-engineered TLS bath. Inside the phononic bandgap, we observe the emergence of non-Markovian qubit dynamics due to the Purcell-engineered TLS lifetime of 34 μs. We discuss the implications of these observations for extending qubit relaxation times through simultaneous phonon protection and miniaturization.},
}

EndNote citation:

%0 Thesis
%A Odeh, Mutasem 
%T Phonon-protected superconducting qubits
%I EECS Department, University of California, Berkeley
%D 2023
%8 December 14
%@ UCB/EECS-2023-269
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/2023/EECS-2023-269.html
%F Odeh:EECS-2023-269