Decoherence benchmarking of superconducting qubits
Artikel i vetenskaplig tidskrift, 2019

We benchmark the decoherence of superconducting transmon qubits to examine the temporal stability of energy relaxation, dephasing, and qubit transition frequency. By collecting statistics during measurements spanning multiple days, we find the mean parameters (T) over bar (1) = 49 mu s and (T) over bar (2)* = 95 mu s; however, both of these quantities fluctuate, explaining the need for frequent re-calibration in qubit setups. Our main finding is that fluctuations in qubit relaxation are local to the qubit and are caused by instabilities of near-resonant two-level-systems (TLS). Through statistical analysis, we determine sub-millihertz switching rates of these TLS and observe the coherent coupling between an individual TLS and a transmon qubit. Finally, we find evidence that the qubit's frequency stability produces a 0.8 ms limit on the pure dephasing which we also observe. These findings raise the need for performing qubit metrology to examine the reproducibility of qubit parameters, where these fluctuations could affect qubit gate fidelity.

circuits

transmon cubbits

resonators

Författare

Jonathan Burnett

National Physical Laboratory (NPL)

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Andreas Bengtsson

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Marco Scigliuzzo

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

David Niepce

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Marina Kudra

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Per Delsing

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

Jonas Bylander

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantteknologi

NPJ QUANTUM INFORMATION

2056-6387 (ISSN)

Vol. 5 1 54

Ämneskategorier

Atom- och molekylfysik och optik

Annan fysik

Annan elektroteknik och elektronik

DOI

10.1038/s41534-019-0168-5

Mer information

Senast uppdaterat

2019-10-23