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Digital Control of Superconducting Qubit Using a Josephson Pulse Generator at 3K

Published

Author(s)

Logan Howe, Manuel Castellanos Beltran, Adam Sirois, David Olaya, John Biesecker, Paul Dresselhaus, Samuel P. Benz, Pete Hopkins

Abstract

Scaling of quantum computers to fault-tolerant levels relies critically on the integration of energy-efficient, stable, and reproducible qubit control and readout electronics. In comparison to traditional semiconductor-control electronics (TSCE) located at room temperature, the signals generated by rf sources based on Josephson-junctions (JJs) benefit from small device sizes, low power dissipation, intrinsic calibration, superior reproducibility, and insensitivity to ambient fluctuations. Previous experiments to colocate qubits and JJ-based control electronics have resulted in quasiparticle poisoning of the qubit, degrading the coherence and lifetime of the qubit. In this paper, we digitally control a 0.01-K transmon qubit with pulses from a Josephson pulse generator (JPG) located at the 3-K stage of a dilution refrigerator. We directly compare the qubit lifetime T1, the coherence time T∗2 , and the thermal occupation Pth when the qubit is controlled by the JPG circuit versus the TSCE setup. We find agreement to within the daily fluctuations of ±0.5 μs and ±2 μs for T1 and T∗2 , respectively, and agreement to within the 1% error for Pth. Additionally, we perform randomized benchmarking to measure an average JPG gate error of 2.1 × 10−2. In combination with a small device size (< 25 mm2) and low on-chip power dissipation ( 100 μW), these results are an important step toward demonstrating the viability of using JJ-based control electronics located at temperature stages higher than the mixing-chamber stage in highly scaled superconducting quantum information systems.
Citation
PRX Quantum
Volume
3
Issue
1

Keywords

Quantum computing, scalable, cryogenic control, Josephson junction (JJ), Single Flux Quantum (SFQ), qubit, transmon, superconductor, voltage metrology

Citation

Howe, L. , Castellanos Beltran, M. , Sirois, A. , Olaya, D. , Biesecker, J. , Dresselhaus, P. , Benz, S. and Hopkins, P. (2022), Digital Control of Superconducting Qubit Using a Josephson Pulse Generator at 3K, PRX Quantum, [online], https://doi.org/10.1103/PRXQuantum.3.010350, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933630 (Accessed April 17, 2024)
Created March 25, 2022, Updated November 29, 2022