Benjamin Villalonga
Research Areas
Authored Publications
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Dynamics of magnetization at infinite temperature in a Heisenberg spin chain
Trond Andersen
Rhine Samajdar
Andre Petukhov
Jesse Hoke
Dmitry Abanin
ILYA Drozdov
Xiao Mi
Alexis Morvan
Charles Neill
Rajeev Acharya
Richard Ross Allen
Kyle Anderson
Markus Ansmann
Frank Arute
Kunal Arya
Juan Atalaya
Gina Bortoli
Alexandre Bourassa
Leon Brill
Michael Broughton
Bob Buckley
Tim Burger
Nicholas Bushnell
Juan Campero
Hung-Shen Chang
Jimmy Chen
Benjamin Chiaro
Desmond Chik
Josh Cogan
Roberto Collins
Paul Conner
William Courtney
Alex Crook
Ben Curtin
Agustin Di Paolo
Andrew Dunsworth
Clint Earle
Lara Faoro
Edward Farhi
Reza Fatemi
Vinicius Ferreira
Ebrahim Forati
Brooks Foxen
Gonzalo Garcia
Élie Genois
William Giang
Dar Gilboa
Raja Gosula
Alejo Grajales Dau
Steve Habegger
Michael Hamilton
Monica Hansen
Sean Harrington
Paula Heu
Gordon Hill
Trent Huang
Ashley Huff
Bill Huggins
Sergei Isakov
Justin Iveland
Cody Jones
Pavol Juhas
Marika Kieferova
Alexei Kitaev
Andrey Klots
Alexander Korotkov
Fedor Kostritsa
John Mark Kreikebaum
Dave Landhuis
Pavel Laptev
Kim Ming Lau
Lily Laws
Joonho Lee
Kenny Lee
Yuri Lensky
Alexander Lill
Wayne Liu
Salvatore Mandra
Orion Martin
Steven Martin
Seneca Meeks
Amanda Mieszala
Shirin Montazeri
Ramis Movassagh
Wojtek Mruczkiewicz
Ani Nersisyan
Michael Newman
JiunHow Ng
Murray Ich Nguyen
Tom O'Brien
Seun Omonije
Alex Opremcak
Rebecca Potter
Leonid Pryadko
David Rhodes
Charles Rocque
Negar Saei
Kannan Sankaragomathi
Henry Schurkus
Christopher Schuster
Mike Shearn
Aaron Shorter
Noah Shutty
Vladimir Shvarts
Vlad Sivak
Jindra Skruzny
Clarke Smith
Rolando Somma
George Sterling
Doug Strain
Marco Szalay
Doug Thor
Alfredo Torres
Guifre Vidal
Cheng Xing
Jamie Yao
Ping Yeh
Juhwan Yoo
Grayson Young
Yaxing Zhang
Ningfeng Zhu
Jeremy Hilton
Anthony Megrant
Yu Chen
Vadim Smelyanskiy
Vedika Khemani
Sarang Gopalakrishnan
Tomaž Prosen
Science, 384(2024), pp. 48-53
Preview abstract
Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain’s center, P(M). The first two moments of P(M) show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments ruled out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide insights into universal behavior in quantum systems.
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Stable quantum-correlated many-body states through engineered dissipation
Xiao Mi
Alexios Michailidis
Sara Shabani
Jerome Lloyd
Rajeev Acharya
Igor Aleiner
Trond Andersen
Markus Ansmann
Frank Arute
Kunal Arya
Juan Atalaya
Gina Bortoli
Alexandre Bourassa
Leon Brill
Michael Broughton
Bob Buckley
Tim Burger
Nicholas Bushnell
Jimmy Chen
Benjamin Chiaro
Desmond Chik
Charina Chou
Josh Cogan
Roberto Collins
Paul Conner
William Courtney
Alex Crook
Ben Curtin
Alejo Grajales Dau
Dripto Debroy
Agustin Di Paolo
ILYA Drozdov
Andrew Dunsworth
Lara Faoro
Edward Farhi
Reza Fatemi
Vinicius Ferreira
Ebrahim Forati
Brooks Foxen
Élie Genois
William Giang
Dar Gilboa
Raja Gosula
Steve Habegger
Michael Hamilton
Monica Hansen
Sean Harrington
Paula Heu
Trent Huang
Ashley Huff
Bill Huggins
Sergei Isakov
Justin Iveland
Cody Jones
Pavol Juhas
Kostyantyn Kechedzhi
Marika Kieferova
Alexei Kitaev
Andrey Klots
Alexander Korotkov
Fedor Kostritsa
John Mark Kreikebaum
Dave Landhuis
Pavel Laptev
Kim Ming Lau
Lily Laws
Joonho Lee
Kenny Lee
Yuri Lensky
Alexander Lill
Wayne Liu
Orion Martin
Amanda Mieszala
Shirin Montazeri
Alexis Morvan
Ramis Movassagh
Wojtek Mruczkiewicz
Charles Neill
Ani Nersisyan
Michael Newman
JiunHow Ng
Murray Ich Nguyen
Tom O'Brien
Alex Opremcak
Andre Petukhov
Rebecca Potter
Leonid Pryadko
Charles Rocque
Negar Saei
Kannan Sankaragomathi
Henry Schurkus
Christopher Schuster
Mike Shearn
Aaron Shorter
Noah Shutty
Vladimir Shvarts
Jindra Skruzny
Clarke Smith
Rolando Somma
George Sterling
Doug Strain
Marco Szalay
Alfredo Torres
Guifre Vidal
Cheng Xing
Jamie Yao
Ping Yeh
Juhwan Yoo
Grayson Young
Yaxing Zhang
Ningfeng Zhu
Jeremy Hilton
Anthony Megrant
Yu Chen
Vadim Smelyanskiy
Dmitry Abanin
Science, 383(2024), pp. 1332-1337
Preview abstract
Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.
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Purification-Based Quantum Error Mitigation of Pair-Correlated Electron Simulations
Thomas E O'Brien
Gian-Luca R. Anselmetti
Fotios Gkritsis
Vincent Elfving
Stefano Polla
William J. Huggins
Oumarou Oumarou
Kostyantyn Kechedzhi
Dmitry Abanin
Rajeev Acharya
Igor Aleiner
Richard Ross Allen
Trond Ikdahl Andersen
Kyle Anderson
Markus Ansmann
Frank Carlton Arute
Kunal Arya
Juan Atalaya
Michael Blythe Broughton
Bob Benjamin Buckley
Alexandre Bourassa
Leon Brill
Tim Burger
Nicholas Bushnell
Jimmy Chen
Yu Chen
Benjamin Chiaro
Desmond Chun Fung Chik
Josh Godfrey Cogan
Roberto Collins
Paul Conner
William Courtney
Alex Crook
Ben Curtin
Ilya Drozdov
Andrew Dunsworth
Daniel Eppens
Lara Faoro
Edward Farhi
Reza Fatemi
Ebrahim Forati
Brooks Riley Foxen
William Giang
Dar Gilboa
Alejandro Grajales Dau
Steve Habegger
Michael C. Hamilton
Sean Harrington
Jeremy Patterson Hilton
Trent Huang
Ashley Anne Huff
Sergei Isakov
Justin Thomas Iveland
Evan Jeffrey
Cody Jones
Pavol Juhas
Dvir Kafri
Julian Kelly
Tanuj Khattar
Mostafa Khezri
Marika Kieferova
Seon Kim
Paul Victor Klimov
Andrey Klots
Alexander Korotkov
Fedor Kostritsa
John Mark Kreikebaum
Dave Landhuis
Pavel Laptev
Kim Ming Lau
Lily MeeKit Laws
Joonho Lee
Kenny Lee
Brian Lester
Alexander T. Lill
Wayne Liu
Aditya Locharla
Erik Lucero
Fionn Malone
Orion Martin
Jarrod Ryan McClean
Trevor Johnathan Mccourt
Matt McEwen
Anthony Megrant
Xiao Mi
Kevin Miao
Masoud Mohseni
Shirin Montazeri
Alexis Morvan
Ramis Movassagh
Wojtek Mruczkiewicz
Ofer Naaman
Matthew Neeley
Charles Neill
Ani Nersisyan
Hartmut Neven
Michael Newman
Jiun How Ng
Anthony Hieu Nguyen
Murray Nguyen
Murphy Yuezhen Niu
Alex Opremcak
Andre Gregory Petukhov
Rebecca Potter
Chris Quintana
Pedram Roushan
Daniel Sank
Kannan Aryaperumal Sankaragomathi
Kevin Satzinger
Christopher Schuster
Mike Shearn
Aaron Shorter
Vladimir Shvarts
Jindra Skruzny
Vadim Smelyanskiy
Clarke Smith
Rolando Diego Somma
Doug Strain
Marco Szalay
Alfredo Torres
Guifre Vidal
Benjamin Villalonga
Bryan W. K. Woo
Ted White
Jamie Yao
Ping Yeh
Juhwan Yoo
Grayson Robert Young
Adam Jozef Zalcman
Yaxing Zhang
Ningfeng Zhu
Nicholas Zobrist
Christian Gogolin
Ryan Babbush
Nicholas Rubin
Nature Physics(2023)
Preview abstract
An important measure of the development of quantum computing platforms has been the simulation of increasingly complex physical systems. Prior to fault-tolerant quantum computing, robust error mitigation strategies are necessary to continue this growth. Here, we study physical simulation within the seniority-zero electron pairing subspace, which affords both a computational stepping stone to a fully correlated model, and an opportunity to validate recently introduced ``purification-based'' error-mitigation strategies. We compare the performance of error mitigation based on doubling quantum resources in time (echo verification) or in space (virtual distillation), on up to 20 qubits of a superconducting qubit quantum processor. We observe a reduction of error by one to two orders of magnitude below less sophisticated techniques (e.g. post-selection); the gain from error mitigation is seen to increase with the system size. Employing these error mitigation strategies enables the implementation of the largest variational algorithm for a correlated chemistry system to-date. Extrapolating performance from these results allows us to estimate minimum requirements for a beyond-classical simulation of electronic structure. We find that, despite the impressive gains from purification-based error mitigation, significant hardware improvements will be required for classically intractable variational chemistry simulations.
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Measurement-induced entanglement and teleportation on a noisy quantum processor
Jesse Hoke
Matteo Ippoliti
Eliott Rosenberg
Dmitry Abanin
Rajeev Acharya
Trond Andersen
Markus Ansmann
Frank Arute
Kunal Arya
Abe Asfaw
Juan Atalaya
Joe Bardin
Andreas Bengtsson
Gina Bortoli
Alexandre Bourassa
Jenna Bovaird
Leon Brill
Michael Broughton
Bob Buckley
David Buell
Tim Burger
Brian Burkett
Nicholas Bushnell
Jimmy Chen
Benjamin Chiaro
Desmond Chik
Josh Cogan
Roberto Collins
Paul Conner
William Courtney
Alex Crook
Ben Curtin
Alejo Grajales Dau
Dripto Debroy
Alexander Del Toro Barba
Sean Demura
Agustin Di Paolo
ILYA Drozdov
Andrew Dunsworth
Daniel Eppens
Catherine Erickson
Edward Farhi
Reza Fatemi
Vinicius Ferreira
Leslie Flores
Ebrahim Forati
Austin Fowler
Brooks Foxen
William Giang
Craig Gidney
Dar Gilboa
Marissa Giustina
Raja Gosula
Jonathan Gross
Steve Habegger
Michael Hamilton
Monica Hansen
Matt Harrigan
Paula Heu
Markus Hoffmann
Sabrina Hong
Trent Huang
Ashley Huff
Bill Huggins
Sergei Isakov
Justin Iveland
Evan Jeffrey
Zhang Jiang
Cody Jones
Pavol Juhas
Dvir Kafri
Kostyantyn Kechedzhi
Tanuj Khattar
Mostafa Khezri
Marika Kieferova
Seon Kim
Alexei Kitaev
Paul Klimov
Andrey Klots
Alexander Korotkov
Fedor Kostritsa
John Mark Kreikebaum
Dave Landhuis
Pavel Laptev
Kim Ming Lau
Lily Laws
Joonho Lee
Kenny Lee
Yuri Lensky
Brian Lester
Alexander Lill
Wayne Liu
Aditya Locharla
Orion Martin
Jarrod McClean
Matt McEwen
Kevin Miao
Amanda Mieszala
Shirin Montazeri
Alexis Morvan
Ramis Movassagh
Wojtek Mruczkiewicz
Matthew Neeley
Charles Neill
Ani Nersisyan
Michael Newman
JiunHow Ng
Anthony Nguyen
Murray Ich Nguyen
Murphy Niu
Tom O'Brien
Seun Omonije
Alex Opremcak
Andre Petukhov
Rebecca Potter
Leonid Pryadko
Chris Quintana
Charles Rocque
Nicholas Rubin
Negar Saei
Daniel Sank
Kannan Sankaragomathi
Kevin Satzinger
Henry Schurkus
Christopher Schuster
Mike Shearn
Aaron Shorter
Noah Shutty
Vladimir Shvarts
Jindra Skruzny
Clarke Smith
Rolando Somma
George Sterling
Doug Strain
Marco Szalay
Alfredo Torres
Guifre Vidal
Benjamin Villalonga
Catherine Vollgraff Heidweiller
Ted White
Bryan Woo
Cheng Xing
Jamie Yao
Ping Yeh
Juhwan Yoo
Grayson Young
Adam Zalcman
Yaxing Zhang
Ningfeng Zhu
Nicholas Zobrist
Hartmut Neven
Ryan Babbush
Dave Bacon
Sergio Boixo
Jeremy Hilton
Erik Lucero
Anthony Megrant
Julian Kelly
Yu Chen
Vadim Smelyanskiy
Xiao Mi
Vedika Khemani
Pedram Roushan
Nature, 622(2023), 481–486
Preview abstract
Measurement has a special role in quantum theory: by collapsing the wavefunction, it can enable phenomena such as teleportation and thereby alter the ‘arrow of time’ that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space–time that go beyond the established paradigms for characterizing phases, either in or out of equilibrium. For present-day noisy intermediate-scale quantum (NISQ) processors, the experimental realization of such physics can be problematic because of hardware limitations and the stochastic nature of quantum measurement. Here we address these experimental challenges and study measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping to avoid mid-circuit measurement and access different manifestations of the underlying phases, from entanglement scaling to measurement-induced teleportation. We obtain finite-sized signatures of a phase transition with a decoding protocol that correlates the experimental measurement with classical simulation data. The phases display remarkably different sensitivity to noise, and we use this disparity to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realizing measurement-induced physics at scales that are at the limits of current NISQ processors.
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Noise-resilient Majorana Edge Modes on a Chain of Superconducting Qubits
Abe Asfaw
Adam Jozef Zalcman
Aditya Locharla
Alejandro Grajales Dau
Alex Crook
Alex Opremcak
Alexa Rubinov
Alexander Korotkov
Alexandre Bourassa
Alexei Kitaev
Alexis Morvan
Andre Gregory Petukhov
Andreas Bengtsson
Andrew Dunsworth
Andrey Klots
Anthony Megrant
Ashley Anne Huff
Austin Fowler
Benjamin Chiaro
Benjamin Villalonga
Bernardo Meurer Costa
Bob Benjamin Buckley
Brian Burkett
Brooks Foxen
Catherine Erickson
Catherine Vollgraff Heidweiller
Charles Neill
Chris Quintana
Christopher Schuster
Cody Jones
Craig Michael Gidney
Daniel Eppens
Daniel Sank
Dar Gilboa
Dave Bacon
Dave Landhuis
David A Buell
Dmitry Abanin
Doug Strain
Dripto M. Debroy
Dvir Kafri
Ebrahim Forati
Edward Farhi
Emily Mount
Erik Lucero
Evan Jeffrey
Fedor Kostritsa
Frank Carlton Arute
Guifre Vidal
Hartmut Neven
Igor Aleiner
Jamie Yao
Jarrod Ryan McClean
Jeremy Patterson Hilton
Joao Basso
Joe Bardin
John Mark Kreikebaum
Jonathan Arthur Gross
Joonho Lee
Juan Atalaya
Juhwan Yoo
Julian Kelly
Justin Thomas Iveland
Kannan Aryaperumal Sankaragomathi
Kenny Lee
Kevin Miao
Kevin Satzinger
Kim Ming Lau
Kostyantyn Kechedzhi
Kunal Arya
Lara Faoro
Leon Brill
Leslie Flores
Lev Ioffe
Marco Szalay
Marissa Giustina
Markus Rudolf Hoffmann
Masoud Mohseni
Matt McEwen
Matt P Harrigan
Matthew Neeley
Michael Blythe Broughton
Michael Newman
Michel Henri Devoret
Mike Shearn
Murphy Yuezhen Niu
Nicholas Bushnell
Nicholas Rubin
Ofer Naaman
Orion Martin
Paul Conner
Paul Victor Klimov
Pavel Laptev
Pedram Roushan
Ping Yeh
Rajeev Acharya
Rebecca Potter
Reza Fatemi
Roberto Collins
Ryan Babbush
Sabrina Hong
Sean Demura
Seon Kim
Sergei Isakov
Sergio Boixo
Shirin Montazeri
Steve Habegger
Tanuj Khattar
Ted White
Thomas E O'Brien
Trent Huang
Trond Ikdahl Andersen
Vadim Smelyanskiy
Vladimir Shvarts
Wayne Liu
William Courtney
William Giang
William J. Huggins
Wojtek Mruczkiewicz
Xiao Mi
Yaxing Zhang
Yu Chen
Yuan Su
Zhang Jiang
Zijun Chen
Science(2022) (to appear)
Preview abstract
Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the kicked Ising model which exhibits Majorana edge modes (MEMs) protected by a $\mathbb{Z}_2$-symmetry. Remarkably, we find that any multi-qubit Pauli operator overlapping with the MEMs exhibits a uniform decay rate comparable to single-qubit relaxation rates, irrespective of its size or composition. This finding allows us to accurately reconstruct the exponentially localized spatial profiles of the MEMs. Spectroscopic measurements further indicate exponentially suppressed hybridization between the MEMs over larger system sizes, which manifests as a strong resilience against low-frequency noise. Our work elucidates the noise sensitivity of symmetry-protected edge modes in a solid-state environment.
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Realizing topologically ordered states on a quantum processor
Kevin Satzinger
Y.-J. Liu
A. Smith
C. Knapp
M. Newman
N. C. Jones
Z. Chen
C. Quintana
X. Mi
A. Dunsworth
C. Gidney
I. Aleiner
F. Arute
K. Arya
J. Atalaya
R. Babbush
J. C. Bardin
R. Barends
J. Basso
A. Bengtsson
A. Bilmes
M. Broughton
B. B. Buckley
D. A. Buell
B. Burkett
N. Bushnell
B. Chiaro
R. Collins
W. Courtney
S. Demura
A. R Derk
D. Eppens
C. Erickson
L. Faoro
E. Farhi
B. Foxen
M. Giustina
A. Greene
J. A. Gross
M. P. Harrigan
S. D. Harrington
J. Hilton
S. Hong
T. Huang
W. J. Huggins
L. B. Ioffe
S. V. Isakov
E. Jeffrey
Z. Jiang
D. Kafri
K. Kechedzhi
T. Khattar
S. Kim
P. V. Klimov
A. N. Korotkov
F. Kostritsa
D. Landhuis
P. Laptev
A. Locharla
E. Lucero
O. Martin
J. R. McClean
M. McEwen
K. C. Miao
M. Mohseni
S. Montazeri
W. Mruczkiewicz
J. Mutus
O. Naaman
M. Neeley
C. Neill
M. Y. Niu
T. E. O'Brien
A. Opremcak
B. Pato
A. Petukhov
N. C. Rubin
D. Sank
V. Shvarts
D. Strain
M. Szalay
B. Villalonga
T. C. White
Z. Yao
P. Yeh
J. Yoo
A. Zalcman
H. Neven
S. Boixo
A. Megrant
Y. Chen
J. Kelly
V. Smelyanskiy
A. Kitaev
M. Knap
F. Pollmann
Pedram Roushan
Science, 374(2021), pp. 1237-1241
Preview abstract
The discovery of topological order has revolutionized the understanding of quantum matter in modern physics and provided the theoretical foundation for many quantum error correcting codes. Realizing topologically ordered states has proven to be extremely challenging in both condensed matter and synthetic quantum systems. Here, we prepare the ground state of the emblematic toric code Hamiltonian using an efficient quantum circuit on a superconducting quantum processor. We measure a topological entanglement entropy of Stopo ≈ −0.95 × ln 2 and simulate anyon interferometry to extract the braiding statistics of the emergent excitations. Furthermore, we investigate key aspects of the surface code, including logical state injection and the decay of the non-local order parameter. Our results illustrate the topological nature of these states and demonstrate their potential for implementing the surface code.
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Exponential suppression of bit or phase flip errors with repetitive quantum error correction
Adam Jozef Zalcman
Alan Derk
Alan Ho
Alex Opremcak
Alexander Korotkov
Alexandre Bourassa
Andre Gregory Petukhov
Andreas Bengtsson
Andrew Dunsworth
Anthony Megrant
Austin Fowler
Bálint Pató
Benjamin Chiaro
Benjamin Villalonga
Brian Burkett
Brooks Riley Foxen
Catherine Erickson
Charles Neill
Chris Quintana
Cody Jones
Craig Michael Gidney
Daniel Eppens
Daniel Sank
Dave Landhuis
David A Buell
Doug Strain
Dvir Kafri
Edward Farhi
Eric Ostby
Erik Lucero
Evan Jeffrey
Fedor Kostritsa
Frank Carlton Arute
Hartmut Neven
Igor Aleiner
Jamie Yao
Jarrod Ryan McClean
Jeremy Patterson Hilton
Jimmy Chen
Jonathan Arthur Gross
Joseph Bardin
Josh Mutus
Juan Atalaya
Julian Kelly
Kevin Miao
Kevin Satzinger
Kostyantyn Kechedzhi
Kunal Arya
Marco Szalay
Marissa Giustina
Masoud Mohseni
Matt McEwen
Matt Trevithick
Matthew Neeley
Matthew P Harrigan
Michael Broughton
Michael Newman
Murphy Yuezhen Niu
Nicholas Bushnell
Nicholas Redd
Nicholas Rubin
Ofer Naaman
Orion Martin
Paul Victor Klimov
Pavel Laptev
Pedram Roushan
Ping Yeh
Rami Barends
Roberto Collins
Ryan Babbush
Sabrina Hong
Sean Demura
Sean Harrington
Seon Kim
Sergei Isakov
Sergio Boixo
Ted White
Thomas E O'Brien
Trent Huang
Trevor Mccourt
Vadim Smelyanskiy
Vladimir Shvarts
William Courtney
Wojtek Mruczkiewicz
Xiao Mi
Yu Chen
Zhang Jiang
Nature(2021)
Preview abstract
Realizing the potential of quantum computing will require achieving sufficiently low logical error rates. Many applications call for error rates below 10^-15, but state-of-the-art quantum platforms typically have physical error rates near 10^-3. Quantum error correction (QEC) promises to bridge this divide by distributing quantum logical information across many physical qubits so that errors can be corrected. Logical errors are then exponentially suppressed as the number of physical qubits grows, provided that the physical error rates are below a certain threshold. QEC also requires that the errors are local, and that performance is maintained over many rounds of error correction, a major outstanding experimental challenge. Here, we implement 1D repetition codes embedded in a 2D grid of superconducting qubits which demonstrate exponential suppression of bit or phase-flip errors, reducing logical error per round by more than 100x when increasing the number of qubits from 5 to 21. Crucially, this error suppression is stable over 50 rounds of error correction. We also introduce a method for analyzing error correlations with high precision, and characterize the locality of errors in a device performing QEC for the first time. Finally, we perform error detection using a small 2D surface code logical qubit on the same device, and show that the results from both 1D and 2D codes agree with numerical simulations using a simple depolarizing error model. These findings demonstrate that superconducting qubits are on a viable path towards fault tolerant quantum computing.
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Tuning Quantum Information Scrambling on a 53-Qubit Processor
Adam Jozef Zalcman
Alan Derk
Alan Ho
Alex Opremcak
Alexander Korotkov
Alexandre Bourassa
Andre Gregory Petukhov
Andreas Bengtsson
Andrew Dunsworth
Anthony Megrant
Austin Fowler
Bálint Pató
Benjamin Chiaro
Benjamin Villalonga
Brian Burkett
Brooks Riley Foxen
Catherine Erickson
Charles Neill
Chris Quintana
Cody Jones
Craig Michael Gidney
Daniel Eppens
Daniel Sank
Dave Landhuis
David A Buell
Doug Strain
Dvir Kafri
Edward Farhi
Eric Ostby
Erik Lucero
Evan Jeffrey
Fedor Kostritsa
Frank Carlton Arute
Hartmut Neven
Igor Aleiner
Jamie Yao
Jarrod Ryan McClean
Jeffrey Marshall
Jeremy Patterson Hilton
Jimmy Chen
Jonathan Arthur Gross
Joseph Bardin
Josh Mutus
Juan Atalaya
Julian Kelly
Kevin Miao
Kevin Satzinger
Kostyantyn Kechedzhi
Kunal Arya
Marco Szalay
Marissa Giustina
Masoud Mohseni
Matt McEwen
Matt Trevithick
Matthew Neeley
Matthew P Harrigan
Michael Blythe Broughton
Michael Newman
Murphy Yuezhen Niu
Nicholas Bushnell
Nicholas Redd
Nicholas Rubin
Ofer Naaman
Orion Martin
Paul Victor Klimov
Pavel Laptev
Pedram Roushan
Ping Yeh
Rami Barends
Roberto Collins
Ryan Babbush
Sabrina Hong
Salvatore Mandra
Sean Demura
Sean Harrington
Seon Kim
Sergei Isakov
Sergio Boixo
Ted White
Thomas E O'Brien
Trent Huang
Trevor Mccourt
Vadim Smelyanskiy
Vladimir Shvarts
William Courtney
Wojtek Mruczkiewicz
Xiao Mi
Yu Chen
Zhang Jiang
arXiv(2021)
Preview abstract
As entanglement in a quantum system grows, initially localized quantum information is spread into the exponentially many degrees of freedom of the entire system. This process, known as quantum scrambling, is computationally intensive to study classically and lies at the heart of several modern physics conundrums. Here, we characterize scrambling of different quantum circuits on a 53-qubit programmable quantum processor by measuring their out-of-time-order correlators (OTOCs). We observe that the spatiotemporal spread of OTOCs, as well as their circuit-to-circuit fluctuation, unravel in detail the time-scale and extent of quantum scrambling. Comparison with numerical results indicates a high OTOC measurement accuracy despite the large size of the quantum system. Our work establishes OTOC as an experimental tool to diagnose quantum scrambling at the threshold of being classically inaccessible.
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Accurately computing electronic properties of materials using eigenenergies
Adam Jozef Zalcman
Alan Derk
Alan Ho
Alex Opremcak
Alexander Korotkov
Andre Gregory Petukhov
Andreas Bengtsson
Andrew Dunsworth
Anthony Megrant
Austin Fowler
Bálint Pató
Benjamin Chiaro
Benjamin Villalonga
Bob Benjamin Buckley
Brian Burkett
Brooks Riley Foxen
Catherine Erickson
Charles Neill
Chris Quintana
Cody Jones
Craig Michael Gidney
Daniel Eppens
Daniel Sank
Dave Landhuis
David A Buell
Doug Strain
Dvir Kafri
Edward Farhi
Eric Ostby
Erik Lucero
Evan Jeffrey
Fedor Kostritsa
Frank Carlton Arute
Hartmut Neven
Igor Aleiner
Jamie Yao
Jarrod Ryan McClean
Jeremy Patterson Hilton
Jimmy Chen
Jonathan Arthur Gross
Joseph Bardin
Josh Mutus
Juan Atalaya
Juan Campero
Julian Kelly
Kevin Miao
Kevin Satzinger
Kostyantyn Kechedzhi
Kunal Arya
Lev Ioffe
Marco Szalay
Marissa Giustina
Masoud Mohseni
Matt Jacob-Mitos
Matt McEwen
Matt Trevithick
Matthew Neeley
Matthew P Harrigan
Michael Blythe Broughton
Michael Newman
Murphy Yuezhen Niu
Nicholas Bushnell
Nicholas Redd
Nicholas Rubin
Ofer Naaman
Orion Martin
Paul Victor Klimov
Pavel Laptev
Pedram Roushan
Ping Yeh
Rami Barends
Roberto Collins
Ryan Babbush
Sabrina Hong
Sean Demura
Sean Harrington
Seon Kim
Sergei Isakov
Sergio Boixo
Ted White
Thomas E O'Brien
Trent Huang
Trevor Mccourt
Vadim Smelyanskiy
Vladimir Shvarts
William Courtney
William J. Huggins
Wojtek Mruczkiewicz
Xiao Mi
Yu Chen
Zhang Jiang
arXiv preprint arXiv:2012.00921(2020)
Preview abstract
A promising approach to study quantum materials is to simulate them on an engineered quantum platform. However, achieving the accuracy needed to outperform classical methods has been an outstanding challenge. Here, using superconducting qubits, we provide an experimental blueprint for a programmable and accurate quantum matter simulator and demonstrate how to probe fundamental electronic properties. We illustrate the underlying method by reconstructing the single-particle band-structure of a one-dimensional wire. We demonstrate nearly complete mitigation of decoherence and readout errors and arrive at an accuracy in measuring energy eigenvalues of this wire with an error of ~0.01 radians, whereas typical energy scales are of order 1 radian. Insight into this unprecedented algorithm fidelity is gained by highlighting robust properties of a Fourier transform, including the ability to resolve eigenenergies with a statistical uncertainty of 1e-4 radians. Furthermore, we synthesize magnetic flux and disordered local potentials, two key tenets of a condensed-matter system. When sweeping the magnetic flux, we observe avoided level crossings in the spectrum, a detailed fingerprint of the spatial distribution of local disorder. Combining these methods, we reconstruct electronic properties of the eigenstates where we observe persistent currents and a strong suppression of conductance with added disorder. Our work describes an accurate method for quantum simulation and paves the way to study novel quantum materials with superconducting qubits.
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