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.
| Original language | English |
|---|---|
| Article number | 080503 |
| Number of pages | 7 |
| Journal | Physical Review Letters |
| Volume | 122 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 25 Feb 2019 |
| MoE publication type | Not Eligible |
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Keywords
- quantum computation
- superconducting qubits
- quantum measurements
- quantum sensing
Cite this
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Qubit Measurement by Multichannel Driving. / Ikonen, Joni; Goetz, Jan; Ilves, Jesper; Keränen, Aarne; Gunyho, Andras M.; Partanen, Matti; Tan, Kuan Y.; Hazra, Dibyendu; Grönberg, Leif; Vesterinen, Visa; Simbierowicz, Slawomir; Hassel, Juha; Möttönen, Mikko.
In: Physical Review Letters, Vol. 122, No. 8, 080503, 25.02.2019.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Qubit Measurement by Multichannel Driving
AU - Ikonen, Joni
AU - Goetz, Jan
AU - Ilves, Jesper
AU - Keränen, Aarne
AU - Gunyho, Andras M.
AU - Partanen, Matti
AU - Tan, Kuan Y.
AU - Hazra, Dibyendu
AU - Grönberg, Leif
AU - Vesterinen, Visa
AU - Simbierowicz, Slawomir
AU - Hassel, Juha
AU - Möttönen, Mikko
PY - 2019/2/25
Y1 - 2019/2/25
N2 - 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.
AB - 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.
KW - quantum computation
KW - superconducting qubits
KW - quantum measurements
KW - quantum sensing
UR - http://www.scopus.com/inward/record.url?scp=85062297443&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.122.080503
DO - 10.1103/PhysRevLett.122.080503
M3 - Article
VL - 122
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 8
M1 - 080503
ER -