Optimal configurations for normal-metal traps in transmon qubits

Abstract

Controlling quasiparticle dynamics can improve the performance of superconducting devices. For example, it has been demonstrated effective in increasing lifetime and stability of superconducting qubits. Here we study how to optimize the placement of normal-metal traps in transmon-type qubits. When the trap size increases beyond a certain characteristic length, the details of the geometry and trap position, and even the number of traps, become important. We discuss for some experimentally relevant examples how to shorten the decay time of the excess quasiparticle density. Moreover, we show that a trap in the vicinity of a Josephson junction can reduce the steady-state quasiparticle density near that junction, thus suppressing the quasiparticle-induced relaxation rate of the qubit. Such a trap also reduces the impact of fluctuations in the generation rate of quasiparticles, rendering the qubit more stable.

arXiv comment16 pages, 7 figures; to appear in Phys. Rev. Applied

References in corpus (24)

• Observation of high coherence in Josephson junction qubits measured in a three-dimensional circuit QED architecture
• Coherent Josephson qubit suitable for scalable quantum integrated circuits
• Single-electron current sources: towards a refined definition of ampere
• Majorana qubit decoherence by quasiparticle poisoning
• Millisecond charge-parity fluctuations and induced decoherence in a superconducting qubit
• Coherent manipulation of Andreev states in superconducting atomic contacts
• Nonequilibrium quasiparticles and $2e$ periodicity in single-Cooper-pair transistors
• Measurement and Control of Quasiparticle Dynamics in a Superconducting Qubit
• Andreev Level Qubit
• Quasiparticle relaxation of superconducting qubits in the presence of flux
• Suppressing relaxation in superconducting qubits by quasiparticle pumping
• Non-Poissonian Quantum Jumps of a Fluxonium Qubit due to Quasiparticle Excitations
• Measurements of Quasiparticle Tunneling Dynamics in a Bandgap-Engineered Transmon Qubit
• Trapping a single vortex and reducing quasiparticles in a superconducting resonator
• Kinetics of non-equilibrium quasiparticle tunneling in superconducting charge qubits
• Vanishing quasiparticle density in a hybrid Al/Cu/Al single-electron transistor
• Normal-metal quasiparticle traps for superconducting qubits
• Phonon-Mediated Quasiparticle Poisoning of Superconducting Microwave Resonators
• Quasiparticle decay rate of Josephson charge qubit oscillations
• A quantitative study of quasiparticle traps using the single-Cooper-pair-transistor
• Quasiparticle trapping in Meissner and vortex states of mesoscopic superconductors
• Efficient Quasiparticle Evacuation in Superconducting Devices
• Quasiparticle diffusion based heating in superconductor tunneling micro-coolers
• Fragility of multi-junction flux qubits against quasiparticle tunneling

Cited by in corpus (15)

• Hot non-equilibrium quasiparticles in transmon qubits
• Digital coherent control of a superconducting qubit
• Phonon traps reduce the quasiparticle density in superconducting circuits
• Quasiparticle poisoning of Majorana qubits
• Bogoliubov Quasiparticles in Superconducting Qubits
• Efficient quasiparticle traps with low dissipation through gap engineering
• Using materials for quasiparticle engineering
• Proximity effect in normal-metal quasiparticle traps
• Identification of different types of high-frequency defects in superconducting qubits
• Non-equilibrium quasiparticles in superconducting circuits: photons vs. phonons
• Testing spontaneous wavefunction collapse with quantum electromechanics
• Charge-parity switching effects and optimisation of transmon-qubit design parameters
• Dissipation by normal-metal traps in transmon qubits
• Quasiparticle Dynamics in Superconducting Quantum-Classical Hybrid Circuits
• A practical guide for building superconducting quantum devices