Qubit Measurement by Multichannel Driving

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openAccess

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Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2019-02-25

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Mcode

Degree programme

Language

en

Pages

1-7

Series

Physical Review Letters, Volume 122, issue 8

Abstract

We theoretically propose and experimentally implement a method of measuring a qubit by driving it close to the frequency of a dispersively coupled bosonic mode. The separation of the bosonic states corresponding to different qubit states begins essentially immediately at maximum rate, leading to a speedup in the measurement protocol. Also the bosonic mode can be simultaneously driven to optimize measurement speed and fidelity. We experimentally test this measurement protocol using a superconducting qubit coupled to a resonator mode. For a certain measurement time, we observe that the conventional dispersive readout yields close to 100% higher average measurement error than our protocol. Finally, we use an additional resonator drive to leave the resonator state to vacuum if the qubit is in the ground state during the measurement protocol. This suggests that the proposed measurement technique may become useful in unconditionally resetting the resonator to a vacuum state after the measurement pulse.

Description

| openaire: EC/H2020/681311/EU//QUESS | openaire: EC/H2020/795159/EU//NEQC

Keywords

Quantum measurement, Superconducting qubit, qubit readout, qubit dynamics

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Citation

Ikonen , J , Goetz , J , Ilves , J , Keränen , A , Gunyho , A , Partanen , M , Tan , K , Hazra , D , Grönberg , L , Vesterinen , V , Simbierowicz , S , Hassel , J & Möttönen , M 2019 , ' Qubit Measurement by Multichannel Driving ' , Physical Review Letters , vol. 122 , no. 8 , 080503 , pp. 1-7 . https://doi.org/10.1103/PhysRevLett.122.080503