Publications (38)
Measurement-induced entanglement and teleportation on a noisy quantum processor
Jesse C. Hoke, Matteo Ippoliti, Eliott Rosenberg +160
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…
Supplementary information for "Quantum supremacy using a programmable superconducting processor"
Frank Arute, Kunal Arya, Ryan Babbush +74
This is an updated version of supplementary information to accompany "Quantum supremacy using a programmable superconducting processor", an article published in the October 24, 201…
Dynamics of magnetization at infinite temperature in a Heisenberg spin chain
Eliott Rosenberg, Trond Andersen, Rhine Samajdar +178
Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the 1D Heisenberg model were conjectured…
Strong environmental coupling in a Josephson parametric amplifier
Josh Mutus, Ted White, Rami Barends +16
We present a lumped-element Josephson parametric amplifier designed to operate with strong coupling to the environment. In this regime, we observe broadband frequency dependent amp…
Balanced Coupling in Electromagnetic Circuits
Daniel Sank, Mostafa Khezri, Sergei Isakov +1
The rotating wave approximation (RWA) is ubiquitous in the analysis of driven and coupled resonators. However, the limitations of the RWA seem to be poorly understood and in some c…
Measurement-induced state transitions in a superconducting qubit: Beyond the rotating wave approximation
Daniel Sank, Zijun Chen, Mostafa Khezri +21
Many superconducting qubit systems use the dispersive interaction between the qubit and a coupled harmonic resonator to perform quantum state measurement. Previous works have found…
Noise-resilient Edge Modes on a Chain of Superconducting Qubits
Xiao Mi, Michael Sonner, Murphy Yuezhen Niu +125
Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental intera…
Suppressing quantum errors by scaling a surface code logical qubit
Rajeev Acharya, Igor Aleiner, Richard Allen +154
Practical quantum computing will require error rates that are well below what is achievable with physical qubits. Quantum error correction offers a path to algorithmically-relevant…
Quantum Approximate Optimization of Non-Planar Graph Problems on a Planar Superconducting Processor
Matthew P. Harrigan, Kevin J. Sung, Matthew Neeley +83
We demonstrate the application of the Google Sycamore superconducting qubit quantum processor to combinatorial optimization problems with the quantum approximate optimization algor…
Resolving catastrophic error bursts from cosmic rays in large arrays of superconducting qubits
Matt McEwen, Lara Faoro, Kunal Arya +50
Scalable quantum computing can become a reality with error correction, provided coherent qubits can be constructed in large arrays. The key premise is that physical errors can rema…
Quantum error correction below the surface code threshold
Rajeev Acharya, Laleh Aghababaie-Beni, Igor Aleiner +246
Quantum error correction provides a path to reach practical quantum computing by combining multiple physical qubits into a logical qubit, where the logical error rate is suppressed…
Information Scrambling in Computationally Complex Quantum Circuits
Xiao Mi, Pedram Roushan, Chris Quintana +90
Interaction in quantum systems can spread initially localized quantum information into the many degrees of freedom of the entire system. Understanding this process, known as quantu…
Computing prime factors with a Josephson phase qubit quantum processor
Erik Lucero, Rami Barends, Yu Chen +11
A quantum processor (QuP) can be used to exploit quantum mechanics to find the prime factors of composite numbers[1]. Compiled versions of Shor's algorithm have been demonstrated o…
Design and characterization of a lumped element single-ended superconducting microwave parametric amplifier with on-chip flux bias line
Josh Mutus, Ted White, Evan Jeffrey +18
We demonstrate a lumped-element Josephson parametric amplifier, using a single-ended design that includes an on-chip, high-bandwidth flux bias line. The amplifier can be pumped int…
Surface spin fluctuations probed with flux noise and coherence in Josephson phase qubits
Daniel Sank, R. Barends, Radoslaw C. Bialczak +15
We measure the dependence of qubit phase coherence and surface spin induced flux noise on inductor loop geometry. While wider inductor traces change neither the flux noise power sp…
Controlled catch and release of microwave photon states
Yi Yin, Yu Chen, Daniel Sank +13
The quantum behavior of superconducting qubits coupled to resonators is very similar to that of atoms in optical cavities [1, 2], in which the resonant cavity confines photons and…
Model-based Optimization of Superconducting Qubit Readout
Andreas Bengtsson, Alex Opremcak, Mostafa Khezri +11
Measurement is an essential component of quantum algorithms, and for superconducting qubits it is often the most error prone. Here, we demonstrate model-based readout optimization…
Quantum Process Tomography of a Universal Entangling Gate Implemented with Josephson Phase Qubits
Radoslaw C. Bialczak, Markus Ansmann, Max Hofheinz +9
Quantum logic gates must perform properly when operating on their standard input basis states, as well as when operating on complex superpositions of these states. Experiments usin…
Sputtered TiN films for superconducting coplanar waveguide resonators
Shinobu Ohya, Ben Chiaro, Anthony Megrant +18
We present a systematic study of the properties of TiN films by varying the deposition conditions in an ultra-high-vacuum reactive magnetron sputtering chamber. By increasing the d…
System Characterization of Dispersive Readout in Superconducting Qubits
Daniel Sank, Alex Opremcak, Andreas Bengtsson +4
Designing quantum systems with the measurement speed and accuracy needed for quantum error correction using superconducting qubits requires iterative design and test informed by ac…
Constructive interference at the edge of quantum ergodic dynamics
Dmitry A. Abanin, Rajeev Acharya, Laleh Aghababaie-Beni +262
Quantum observables in the form of few-point correlators are the key to characterizing the dynamics of quantum many-body systems. In dynamics with fast entanglement generation, qua…
Non-Abelian braiding of graph vertices in a superconducting processor
Trond I. Andersen, Yuri D. Lensky, Kostyantyn Kechedzhi +166
Indistinguishability of particles is a fundamental principle of quantum mechanics. For all elementary and quasiparticles observed to date - including fermions, bosons, and Abelian…
Exponential suppression of bit or phase flip errors with repetitive error correction
Zijun Chen, Kevin J. Satzinger, Juan Atalaya +88
Realizing the potential of quantum computing will require achieving sufficiently low logical error rates. Many applications call for error rates in the regime, but state…
Fluctuations of Energy-Relaxation Times in Superconducting Qubits
P. V. Klimov, J. Kelly, Z. Chen +30
Superconducting qubits are an attractive platform for quantum computing since they have demonstrated high-fidelity quantum gates and extensibility to modest system sizes. Nonethele…
Overcoming leakage in scalable quantum error correction
Kevin C. Miao, Matt McEwen, Juan Atalaya +114
Leakage of quantum information out of computational states into higher energy states represents a major challenge in the pursuit of quantum error correction (QEC). In a QEC circuit…
Fast Scalable State Measurement with Superconducting Qubits
Daniel Sank, Evan Jeffrey, J. Y. Mutus +15
Progress in superconducting qubit experiments with greater numbers of qubits or advanced techniques such as feedback requires faster and more accurate state measurement. We have de…
Readout of a quantum processor with high dynamic range Josephson parametric amplifiers
T. C. White, Alex Opremcak, George Sterling +91
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…
Observation of Time-Crystalline Eigenstate Order on a Quantum Processor
Xiao Mi, Matteo Ippoliti, Chris Quintana +102
Quantum many-body systems display rich phase structure in their low-temperature equilibrium states. However, much of nature is not in thermal equilibrium. Remarkably, it was recent…
A 28nm Bulk-CMOS 4-to-8GHz <2mW Cryogenic Pulse Modulator for Scalable Quantum Computing
Joseph C Bardin, Evan Jeffrey, Erik Lucero +28
Future quantum computing systems will require cryogenic integrated circuits to control and measure millions of qubits. In this paper, we report the design and characterization of a…
Measurement-Induced State transitions in Inductively-Shunted Transmons
Nicholas Zobrist, John Mark Kreikebaum, Mostafa Khezri +6
Fast and high-fidelity qubit measurement plays a key role in quantum error correction. In superconducting qubits, measurement is typically performed using a resonant microwave driv…
Reduced phase error through optimized control of a superconducting qubit
Erik Lucero, Julian Kelly, Radoslaw C. Bialczak +11
Minimizing phase and other errors in experimental quantum gates allows higher fidelity quantum processing. To quantify and correct for phase errors in particular, we have developed…
Hartree-Fock on a superconducting qubit quantum computer
Frank Arute, Kunal Arya, Ryan Babbush +79
As the search continues for useful applications of noisy intermediate scale quantum devices, variational simulations of fermionic systems remain one of the most promising direction…
Compressed sensing quantum process tomography for superconducting quantum gates
Andrey V. Rodionov, Andrzej Veitia, R. Barends +6
We apply the method of compressed sensing (CS) quantum process tomography (QPT) to characterize quantum gates based on superconducting Xmon and phase qubits. Using experimental dat…
Resisting high-energy impact events through gap engineering in superconducting qubit arrays
Matt McEwen, Kevin C. Miao, Juan Atalaya +24
Quantum error correction (QEC) provides a practical path to fault-tolerant quantum computing through scaling to large qubit numbers, assuming that physical errors are sufficiently…
Observation of separated dynamics of charge and spin in the Fermi-Hubbard model
Frank Arute, Kunal Arya, Ryan Babbush +96
Strongly correlated quantum systems give rise to many exotic physical phenomena, including high-temperature superconductivity. Simulating these systems on quantum computers may avo…
Formation of robust bound states of interacting microwave photons
Alexis Morvan, Trond I. Andersen, Xiao Mi +147
Systems of correlated particles appear in many fields of science and represent some of the most intractable puzzles in nature. The computational challenge in these systems arises w…
Measurement-Induced State Transitions in a Superconducting Qubit: Within the Rotating Wave Approximation
Mostafa Khezri, Alex Opremcak, Zijun Chen +9
Superconducting qubits typically use a dispersive readout scheme, where a resonator is coupled to a qubit such that its frequency is qubit-state dependent. Measurement is performed…
Fabrication and Characterization of Aluminum Airbridges for Superconducting Microwave Circuits
Zijun Chen, Anthony Megrant, Julian Kelly +16
Superconducting microwave circuits based on coplanar waveguides (CPW) are susceptible to parasitic slotline modes which can lead to loss and decoherence. We motivate the use of sup…