Readout of a quantum processor with high dynamic range Josephson parametric amplifiers
Creators: name: White, T. C.
name: Opremcak, Alex
name: Sterling, George
name: Korotkov, Alexander
name: Sank, Daniel
name: Acharya, Rajeev
name: Ansmann, Markus
name: Arute, Frank
name: Arya, Kunal
name: Bardin, Joseph C.
name: Bengtsson, Andreas
name: Bourassa, Alexandre
name: Bovaird, Jenna
name: Brill, Leon
name: Buckley, Bob B.
name: Buell, David A.
name: Burger, Tim
name: Burkett, Brian
name: Bushnell, Nicholas
name: Chen, Zijun
name: Chiaro, Ben
name: Cogan, Josh
name: Collins, Roberto
name: Crook, Alexander L.
name: Curtin, Ben
name: Demura, Sean
name: Dunsworth, Andrew
name: Erickson, Catherine
name: Fatemi, Reza
name: Flores-Burgos, Leslie
name: Forati, Ebrahim
name: Foxen, Brooks
name: Giang, William
name: Giustina, Marissa
name: Dau, Alejandro Grajales
name: Hamilton, Michael C.
name: Harrington, Sean D.
name: Hilton, Jeremy
name: Hoffmann, Markus
name: Hong, Sabrina
name: Huang, Trent
name: Huff, Ashley
name: Iveland, Justin
name: Jeffrey, Evan
name: Kieferová, Márika
name: Kim, Seon
name: Klimov, Paul V.
name: Kostritsa, Fedor
name: Kreikebaum, John Mark
name: Landhuis, David
name: Laptev, Pavel
name: Laws, Lily
name: Lee, Kenny
name: Lester, Brian J.
name: Lill, Alexander
name: Liu, Wayne
name: Locharla, Aditya
name: Lucero, Erik
name: McCourt, Trevor
name: McEwen, Matt
name: Mi, Xiao
name: Miao, Kevin C.
name: Montazeri, Shirin
name: Morvan, Alexis
name: Neeley, Matthew
name: Neill, Charles
name: Nersisyan, Ani
name: Ng, Jiun How
name: Nguyen, Anthony
name: Nguyen, Murray
name: Potter, Rebecca
name: Quintana, Chris
name: Roushan, Pedram
name: Sankaragomathi, Kannan
name: Satzinger, Kevin J.
name: Schuster, Christopher
name: Shearn, Michael J.
name: Shorter, Aaron
name: Shvarts, Vladimir
name: Skruzny, Jindra
name: Smith, W. Clarke
name: Szalay, Marco
name: Torres, Alfredo
name: Woo, Bryan
name: Yao, Z. Jamie
name: Yeh, Ping
name: Yoo, Juhwan
name: Young, Grayson
name: Zhu, Ningfeng
name: Zobrist, Nicholas
name: Chen, Yu
name: Megrant, Anthony
name: Kelly, Julian
name: Naaman, Ofer
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Superconductivity (cond-mat.supr-con)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We demonstrate a high dynamic range Josephson parametric amplifier (JPA) in which the active nonlinear element is implemented using an array of rf-SQUIDs. The device is matched to the 50 $Ω$ environment with a Klopfenstein-taper impedance transformer and achieves a bandwidth of 250-300 MHz, with input saturation powers up to -95 dBm at 20 dB gain. A 54-qubit Sycamore processor was used to benchmark these devices, providing a calibration for readout power, an estimate of amplifier added noise, and a platform for comparison against standard impedance matched parametric amplifiers with a single dc-SQUID. We find that the high power rf-SQUID array design has no adverse effect on system noise, readout fidelity, or qubit dephasing, and we estimate an upper bound on amplifier added noise at 1.6 times the quantum limit. Lastly, amplifiers with this design show no degradation in readout fidelity due to gain compression, which can occur in multi-tone multiplexed readout with traditional JPAs.
description: 10 pages, 10 figures