| Title: |
Fast Multiplexed Superconducting-Qubit Readout with Intrinsic Purcell Filtering Using a Multiconductor Transmission Line |
| Authors: |
Spring, Peter A.; Milanovic, Luka; Sunada, Yoshiki; Wang, Shiyu; Van Loo, Arjan F.; Tamate, Shuhei; Nakamura, Yasunobu |
| Contributors: |
Department of Applied Physics; Quantum Computing and Devices; Centre of Excellence in Quantum Technology, QTF; RIKEN Center for Quantum Computing; Aalto-yliopisto; Aalto University |
| Publisher Information: |
American Physical Society |
| Publication Year: |
2025 |
| Collection: |
Aalto University Publication Archive (Aaltodoc) / Aalto-yliopiston julkaisuarkistoa |
| Description: |
Publisher Copyright: © 2025 authors. Published by the American Physical Society. ; Fast and accurate qubit measurement remains a critical challenge on the path to fault-tolerant quantum computing. In superconducting quantum circuits, fast qubit measurement has been achieved using a dispersively coupled resonator with a large externally limited linewidth. This necessitates the use of a Purcell filter that protects the qubit from relaxation through the readout channel. Here, we show that a readout resonator and filter resonator, coupled to each other both capacitively and inductively via a multiconductor transmission line, can produce a compact notch-filter circuit that effectively eliminates the Purcell decay channel through destructive interference. By utilizing linewidths as large as 42 MHz, we perform simultaneous readout of four qubits using a 56-ns integration window and benchmark an average assignment fidelity of 99.77%, with the highest qubit assignment fidelity exceeding 99.9%. Including the simulated readout ring-down time, the total readout duration was between 115 and 215 ns for the four qubits, which we anticipate can be reduced to around 100 ns with active ring-down pulse shaping. These results demonstrate a significant advancement in speed and fidelity for multiplexed superconducting-qubit readout. ; Peer reviewed |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
PRX Quantum; Volume 6, issue 2, pp. 1-23; https://aaltodoc.aalto.fi/handle/123456789/137318 |
| DOI: |
10.1103/PRXQuantum.6.020345 |
| Availability: |
https://aaltodoc.aalto.fi/handle/123456789/137318; https://doi.org/10.1103/PRXQuantum.6.020345 |
| Rights: |
openAccess ; CC BY ; https://creativecommons.org/licenses/by/4.0/ |
| Accession Number: |
edsbas.B55E15CD |
| Database: |
BASE |