In circuit quantum electrodynamics, qubits are typically measured using dispersively coupled readout resonators. Coupling between each readout resonator and its electrical environment, however, reduces the qubit lifetime via the Purcell effect. Inserting a Purcell filter counters this effect while maintaining high readout fidelity but reduces measurement bandwidth and, thus, limits multiplexing readout capacity. In this Letter, we develop and implement a multi-stage bandpass Purcell filter that yields better qubit protection while simultaneously increasing measurement bandwidth and multiplexed capacity. We report on the experimental performance of our transmission-line-based implementation of this approach, a flexible design that can easily be integrated with current scaled-up, long coherence time superconducting quantum processors.

1.
A.
Blais
,
A. L.
Grimsmo
,
S.
Girvin
, and
A.
Wallraff
, “
Circuit quantum electrodynamics
,”
Rev. Mod. Phys.
93
,
025005
(
2021
).
2.
A.
Wallraff
,
D. I.
Schuster
,
A.
Blais
,
L.
Frunzio
,
J.
Majer
,
M. H.
Devoret
,
S. M.
Girvin
, and
R. J.
Schoelkopf
, “
Approaching unit visibility for control of a superconducting qubit with dispersive readout
,”
Phys. Rev. Lett.
95
,
060501
(
2005
).
3.
J.
Koch
,
T. M.
Yu
,
J.
Gambetta
,
A. A.
Houck
,
D. I.
Schuster
,
J.
Majer
,
A.
Blais
,
M. H.
Devoret
,
S. M.
Girvin
, and
R. J.
Schoelkopf
, “
Charge-insensitive qubit design derived from the Cooper pair box
,”
Phys. Rev. A
76
,
042319
(
2007
).
4.
E. M.
Purcell
, “
Spontaneous emission probabilities at radio frequencies
,” in
Confined Electrons and Photons
(
Springer US
,
1995
) pp.
839
839
.
5.
M. D.
Reed
,
B. R.
Johnson
,
A. A.
Houck
,
L.
DiCarlo
,
J. M.
Chow
,
D. I.
Schuster
,
L.
Frunzio
, and
R. J.
Schoelkopf
, “
Fast reset and suppressing spontaneous emission of a superconducting qubit
,”
Appl. Phys. Lett.
96
,
203110
(
2010
).
6.
E.
Jeffrey
,
D.
Sank
,
J.
Mutus
,
T.
White
,
J.
Kelly
,
R.
Barends
,
Y.
Chen
,
Z.
Chen
,
B.
Chiaro
,
A.
Dunsworth
,
A.
Megrant
,
P.
O'Malley
,
C.
Neill
,
P.
Roushan
,
A.
Vainsencher
,
J.
Wenner
,
A.
Cleland
, and
J. M.
Martinis
, “
Fast accurate state measurement with superconducting qubits
,”
Phys. Rev. Lett.
112
,
190504
(
2014
).
7.
D. T.
Sank
, “
Fast, accurate state measurement in superconducting qubits
,” Ph.D. thesis (
University of California
,
Santa Barbara
,
2014
).
8.
E. A.
Sete
,
J. M.
Martinis
, and
A. N.
Korotkov
, “
Quantum theory of a bandpass Purcell filter for qubit readout
,”
Phys. Rev. A
92
,
012325
(
2015
).
9.
T.
Walter
,
P.
Kurpiers
,
S.
Gasparinetti
,
P.
Magnard
,
A.
Potočnik
,
Y.
Salathé
,
M.
Pechal
,
M.
Mondal
,
M.
Oppliger
,
C.
Eichler
, and
A.
Wallraff
, “
Rapid high-fidelity single-shot dispersive readout of superconducting qubits
,”
Phys. Rev. Appl.
7
,
054020
(
2017
).
10.
Y.
Sunada
,
S.
Kono
,
J.
Ilves
,
S.
Tamate
,
T.
Sugiyama
,
Y.
Tabuchi
, and
Y.
Nakamura
, “
Fast readout and reset of a superconducting qubit coupled to a resonator with an intrinsic Purcell filter
,”
Phys. Rev. Appl.
17
,
044016
(
2022
).
11.
L.
Chen
,
H.-X.
Li
,
Y.
Lu
,
C. W.
Warren
,
C. J.
Križan
,
S.
Kosen
,
M.
Rommel
,
S.
Ahmed
,
A.
Osman
,
J.
Biznárová
,
A. F.
Roudsari
,
B.
Lienhard
,
M.
Caputo
,
K.
Grigoras
,
L.
Grönberg
,
J.
Govenius
,
A. F.
Kockum
,
P.
Delsing
,
J.
Bylander
, and
G.
Tancredi
, “
Transmon qubit readout fidelity at the threshold for quantum error correction without a quantum-limited amplifier
,”
npj Quantum Inf.
9
,
26
(
2023
).
12.
A. P. M.
Place
,
L. V. H.
Rodgers
,
P.
Mundada
,
B. M.
Smitham
,
M.
Fitzpatrick
,
Z.
Leng
,
A.
Premkumar
,
J.
Bryon
,
A.
Vrajitoarea
,
S.
Sussman
,
G.
Cheng
,
T.
Madhavan
,
H. K.
Babla
,
X. H.
Le
,
Y.
Gang
,
B.
Jäck
,
A.
Gyenis
,
N.
Yao
,
R. J.
Cava
,
N. P.
de Leon
, and
A. A.
Houck
, “
New material platform for superconducting transmon qubits with coherence times exceeding 0.3 milliseconds
,”
Nat. Commun.
12
,
1779
(
2021
).
13.
C.
Wang
,
X.
Li
,
H.
Xu
,
Z.
Li
,
J.
Wang
,
Z.
Yang
,
Z.
Mi
,
X.
Liang
,
T.
Su
,
C.
Yang
,
G.
Wang
,
W.
Wang
,
Y.
Li
,
M.
Chen
,
C.
Li
,
K.
Linghu
,
J.
Han
,
Y.
Zhang
,
Y.
Feng
,
Y.
Song
,
T.
Ma
,
J.
Zhang
,
R.
Wang
,
P.
Zhao
,
W.
Liu
,
G.
Xue
,
Y.
Jin
, and
H.
Yu
, “
Towards practical quantum computers: Transmon qubit with a lifetime approaching 0.5 milliseconds
,”
npj Quantum Inf.
8
,
3
(
2022
).
14.
J.
Heinsoo
,
C. K.
Andersen
,
A.
Remm
,
S.
Krinner
,
T.
Walter
,
Y.
Salathé
,
S.
Gasparinetti
,
J.-C.
Besse
,
A.
Potočnik
,
A.
Wallraff
, and
C.
Eichler
, “
Rapid high-fidelity multiplexed readout of superconducting qubits
,”
Phys. Rev. Appl.
10
,
034040
(
2018
).
15.
B.
Saxberg
,
A.
Vrajitoarea
,
G.
Roberts
,
M. G.
Panetta
,
J.
Simon
, and
D. I.
Schuster
, “
Disorder-assisted assembly of strongly correlated fluids of light
,”
Nature
612
,
435
441
(
2022
).
16.
G.
Matthaei
,
E. M. T.
Jones
, and
L.
Young
,
Microwave Filters, Impedance-Matching Networks, and Coupling Structures
(
Artech House Publishers
,
1980
).
17.
D. M.
Pozar
,
Microwave Engineering
(
Wiley
,
2011
).
18.
H. R.
Mohebbi
,
O.
Benningshof
,
I.
Taminiau
,
G.-X.
Miao
, and
D.
Cory
, “
Superconducting coplanar interdigital filter with robust packaging
,”
IEEE Trans. Appl. Supercond.
25
,
1500604
(
2015
).
19.
N. T.
Bronn
,
Y.
Liu
,
J. B.
Hertzberg
,
A. D.
Córcoles
,
A. A.
Houck
,
J. M.
Gambetta
, and
J. M.
Chow
, “
Broadband filters for abatement of spontaneous emission in circuit quantum electrodynamics
,”
Appl. Phys. Lett.
107
,
172601
(
2015
).
20.
Z.
Li
,
T.
Roy
,
D. R.
Perez
,
K.-H.
Lee
,
E.
Kapit
, and
D. I.
Schuster
, “
Autonomous error correction of a single logical qubit using two transmons
,” arXiv:2302.06707 [quant-ph]. (
2023
).
21.
A. Y.
Cleland
,
M.
Pechal
,
P.-J. C.
Stas
,
C. J.
Sarabalis
,
E. A.
Wollack
, and
A. H.
Safavi-Naeini
, “
Mechanical Purcell filters for microwave quantum machines
,”
Appl. Phys. Lett.
115
,
263504
(
2019
).
22.
X.
Zhang
,
E.
Kim
,
D. K.
Mark
,
S.
Choi
, and
O.
Painter
, “
A superconducting quantum simulator based on a photonic-bandgap metamaterial
,”
Science
379
,
278
283
(
2023
).
23.
V. S.
Ferreira
,
G.
Kim
,
A.
Butler
,
H.
Pichler
, and
O.
Painter
, “
Deterministic generation of multidimensional photonic cluster states with a single quantum emitter
,” arXiv:2206.10076 [quant-ph]. (
2022
).
24.
O.
Naaman
and
J.
Aumentado
, “
Synthesis of parametrically coupled networks
,”
PRX Quantum
3
,
020201
(
2022
).
25.
Z.
Wang
,
Z.
Bao
,
Y.
Wu
,
Y.
Li
,
C.
Ma
,
T.
Cai
,
Y.
Song
,
H.
Zhang
, and
L.
Duan
, “
Improved superconducting qubit state readout by path interference
,”
Chin. Phys. Lett.
38
,
110303
(
2021
).
26.
T.
Roy
,
S.
Kundu
,
M.
Chand
,
A. M.
Vadiraj
,
A.
Ranadive
,
N.
Nehra
,
M. P.
Patankar
,
J.
Aumentado
,
A. A.
Clerk
, and
R.
Vijay
, “
Broadband parametric amplification with impedance engineering: Beyond the gain-bandwidth product
,”
Appl. Phys. Lett.
107
,
262601
(
2015
).
27.
J.
Grebel
,
A.
Bienfait
,
É.
Dumur
,
H.-S.
Chang
,
M.-H.
Chou
,
C. R.
Conner
,
G. A.
Peairs
,
R. G.
Povey
,
Y. P.
Zhong
, and
A. N.
Cleland
, “
Flux-pumped impedance-engineered broadband Josephson parametric amplifier
,”
Appl. Phys. Lett.
118
,
142601
(
2021
).
28.
T.
White
,
A.
Opremcak
,
G.
Sterling
,
A.
Korotkov
,
D.
Sank
,
R.
Acharya
,
M.
Ansmann
,
F.
Arute
,
K.
Arya
,
J. C.
Bardin
,
A.
Bengtsson
,
A.
Bourassa
,
J.
Bovaird
,
L.
Brill
,
B. B.
Buckley
,
D. A.
Buell
,
T.
Burger
,
B.
Burkett
,
N.
Bushnell
,
Z.
Chen
,
B.
Chiaro
,
J.
Cogan
,
R.
Collins
,
A. L.
Crook
,
B.
Curtin
,
S.
Demura
,
A.
Dunsworth
,
C.
Erickson
,
R.
Fatemi
,
L. F.
Burgos
,
E.
Forati
,
B.
Foxen
,
W.
Giang
,
M.
Giustina
,
A. G.
Dau
,
M. C.
Hamilton
,
S. D.
Harrington
,
J.
Hilton
,
M.
Hoffmann
,
S.
Hong
,
T.
Huang
,
A.
Huff
,
J.
Iveland
,
E.
Jeffrey
,
M.
Kieferová
,
S.
Kim
,
P. V.
Klimov
,
F.
Kostritsa
,
J. M.
Kreikebaum
,
D.
Landhuis
,
P.
Laptev
,
L.
Laws
,
K.
Lee
,
B. J.
Lester
,
A.
Lill
,
W.
Liu
,
A.
Locharla
,
E.
Lucero
,
T.
McCourt
,
M.
McEwen
,
X.
Mi
,
K. C.
Miao
,
S.
Montazeri
,
A.
Morvan
,
M.
Neeley
,
C.
Neill
,
A.
Nersisyan
,
J. H.
Ng
,
A.
Nguyen
,
M.
Nguyen
,
R.
Potter
,
C.
Quintana
,
P.
Roushan
,
K.
Sankaragomathi
,
K. J.
Satzinger
,
C.
Schuster
,
M. J.
Shearn
,
A.
Shorter
,
V.
Shvarts
,
J.
Skruzny
,
W. C.
Smith
,
M.
Szalay
,
A.
Torres
,
B. W. K.
Woo
,
Z. J.
Yao
,
P.
Yeh
,
J.
Yoo
,
G.
Young
,
N.
Zhu
,
N.
Zobrist
,
Y.
Chen
,
A.
Megrant
,
J.
Kelly
, and
O.
Naaman
, “
Readout of a quantum processor with high dynamic range Josephson parametric amplifiers
,”
Appl. Phys. Lett.
122
,
014001
(
2023
).
29.
R.
Kaufman
,
T.
White
,
M. I.
Dykman
,
A.
Iorio
,
G.
Stirling
,
S.
Hong
,
A.
Opremcak
,
A.
Bengtsson
,
L.
Faoro
,
J. C.
Bardin
,
T.
Burger
,
R.
Gasca
, and
O.
Naaman
, “
Josephson parametric amplifier with Chebyshev gain profile and high saturation
,” arXiv:2305.17816 [quant-ph]. (
2023
).
30.
M. A.
Beck
,
M.
Selvanayagam
,
A.
Carniol
,
S.
Cairns
, and
C. P.
Mancini
, “
Wideband Josephson parametric isolator
,” arXiv:2212.08563 [quant-ph]. (
2022
).
31.
R.
Kwende
,
T.
White
, and
O.
Naaman
, “
Josephson parametric circulator with same-frequency signal ports, 200 MHz bandwidth, and high dynamic range
,”
Appl. Phys. Lett.
122
,
224001
(
2023
).
32.
W. A.
Harrison
,
Solid State Theory
(
Courier Corporation
,
1980
).
33.
H.
Bruus
and
K.
Flensberg
,
Many-Body Quantum Theory in Condensed Matter Physics
(
Oxford University Press
,
2004
).
34.
A. A.
Clerk
,
M. H.
Devoret
,
S. M.
Girvin
,
F.
Marquardt
, and
R. J.
Schoelkopf
, “
Introduction to quantum noise, measurement, and amplification
,”
Rev. Mod. Phys.
82
,
1155
1208
(
2010
).
35.
R.
Barends
,
J.
Kelly
,
A.
Megrant
,
D.
Sank
,
E.
Jeffrey
,
Y.
Chen
,
Y.
Yin
,
B.
Chiaro
,
J.
Mutus
,
C.
Neill
,
P.
O'Malley
,
P.
Roushan
,
J.
Wenner
,
T. C.
White
,
A. N.
Cleland
, and
J. M.
Martinis
, “
Coherent Josephson qubit suitable for scalable quantum integrated circuits
,”
Phys. Rev. Lett.
111
,
080502
(
2013
).
36.
A.
Bienfait
,
K. J.
Satzinger
,
Y. P.
Zhong
,
H.-S.
Chang
,
M.-H.
Chou
,
C. R.
Conner
,
É.
Dumur
,
J.
Grebel
,
G. A.
Peairs
,
R. G.
Povey
, and
A. N.
Cleland
, “
Phonon-mediated quantum state transfer and remote qubit entanglement
,”
Science
364
,
368
371
(
2019
).
37.
Y.
Zhong
,
H.-S.
Chang
,
A.
Bienfait
,
É.
Dumur
,
M.-H.
Chou
,
C. R.
Conner
,
J.
Grebel
,
R. G.
Povey
,
H.
Yan
,
D. I.
Schuster
, and
A. N.
Cleland
, “
Deterministic multi-qubit entanglement in a quantum network
,”
Nature
590
,
571
575
(
2021
).
38.
Y.
Chu
and
S.
Gröblacher
, “
A perspective on hybrid quantum opto- and electromechanical systems
,”
Appl. Phys. Lett.
117
,
150503
(
2020
).
39.
M.
Scigliuzzo
,
G.
Calajò
,
F.
Ciccarello
,
D. P.
Lozano
,
A.
Bengtsson
,
P.
Scarlino
,
A.
Wallraff
,
D.
Chang
,
P.
Delsing
, and
S.
Gasparinetti
, “
Controlling atom-photon bound states in an array of Josephson-junction resonators
,”
Phys. Rev. X
12
,
031036
(
2022
).
40.
G. J.
Dolan
, “
Offset masks for lift-off photoprocessing
,”
Appl. Phys. Lett.
31
,
337
339
(
1977
).
41.
K. J.
Satzinger
,
C. R.
Conner
,
A.
Bienfait
,
H.-S.
Chang
,
M.-H.
Chou
,
A. Y.
Cleland
,
É.
Dumur
,
J.
Grebel
,
G. A.
Peairs
,
R. G.
Povey
,
S. J.
Whiteley
,
Y. P.
Zhong
,
D. D.
Awschalom
,
D. I.
Schuster
, and
A. N.
Cleland
, “
Simple non-galvanic flip-chip integration method for hybrid quantum systems
,”
Appl. Phys. Lett.
114
,
173501
(
2019
).
42.
C. R.
Conner
,
A.
Bienfait
,
H.-S.
Chang
,
M.-H.
Chou
,
É.
Dumur
,
J.
Grebel
,
G. A.
Peairs
,
R. G.
Povey
,
H.
Yan
,
Y. P.
Zhong
, and
A. N.
Cleland
, “
Superconducting qubits in a flip-chip architecture
,”
Appl. Phys. Lett.
118
,
232602
(
2021
).
43.
C.
Macklin
,
K.
O'Brien
,
D.
Hover
,
M. E.
Schwartz
,
V.
Bolkhovsky
,
X.
Zhang
,
W. D.
Oliver
, and
I.
Siddiqi
, “
A near–quantum-limited Josephson traveling-wave parametric amplifier
,”
Science
350
,
307
310
(
2015
).
44.
H.-X.
Li
,
D.
Shiri
,
S.
Kosen
,
M.
Rommel
,
L.
Chayanum
,
A.
Nylander
,
R.
Rehammer
,
G.
Tancredi
,
M.
Caputo
,
K.
Grigoras
,
L.
Grönberg
,
J.
Govenius
, and
J.
Bylander
, “
Experimentally verified, fast analytic, and numerical design of superconducting resonators in flip-chip architectures
,”
IEEE Trans. Quantum Eng.
4
,
3101312
(
2023
).

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