Decoherence in Josephson qubits from dielectric loss.

By John M. Martinis, K. Cooper, R. McDermott, Matthias Steffen, M. Ansmann, K. Osborn, Katarina Cicak, Seongshik Oh, David P. Pappas, Raymond W. Simmonds and 1 more. Physical Review Letters, 2005

746 citations recorded by the source corpus.

Dielectric loss from two-level states is shown to be a dominant decoherence source in superconducting quantum bits. Depending on the qubit design, dielectric loss from insulating materials or the tunnel junction can lead to short coherence times. We show that a variety of microwave and qubit measurements are well modeled by loss from resonant absorption of two-level defects. Our results demonstrate that this loss can be significantly reduced by using better dielectrics and fabricating junctions of small area . With a redesigned phase qubit employing low-loss dielectrics, the energy relaxation rate has been improved by a factor of 20, opening up the possibility of multiqubit gates and algorithms.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics, Condensed Matter Physics

View Paper: https://www.semanticscholar.org/paper/13d6b72814cfaff299f52ee3f55094c9022001d8

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In Artificial Intelligence

In Atomic and Molecular Physics, and Optics

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Jiansong Gao

Citations in the corpus

1 / f noise: Implications for solid-state quantum information (2013, background): “In some cases, the decoherence is predicted to be limited by the energy relaxation, T2 ∼ 2T1, which occurs due to dielectric losses (Martinis et al., 2005) and quasiparticle tunneling (Lutchin et al.”
Three-Dimensional Superconducting Resonators at T<20 mK with Photon Lifetimes up to τ=2 s (2018, methodology): “Recent investigations [8] have revealed that the twolevel systems (TLS) residing inside niobium oxide may play a significant role in the low-field performance of SRF cavities, similar to two-dimensional (2D) resonators [9,10].”
Parametrically Activated Entangling Gates Using Transmon Qubits (2017, result): “In principle the flux modulation may also increase the qubit’s relaxation rate [15, 33], but we found that T1 was consistent with the flux drive on versus off.”
Decoherence in solid-state qubits (2008, neutral): “Recent experiments [112, 113 ] have pointed out that a dominant source of decoherence for the phase qubit is represented by low frequency 1/f noise, that is believed to arise from two level systems (TLS) in the insulating barrier of the tunnel junction as well as in the dielectric material surroundi”