926 citations · 8.7k across the 34 of their papers we have counts for
35 papers
Physical qubit calibration on a directed acyclic graph
Julian Kelly, Peter O'Malley, Matthew Neeley +2
High-fidelity control of qubits requires precisely tuned control parameters. Typically, these parameters are found through a series of bootstrapped calibration experiments which su…
Observation of classical-quantum crossover of 1/f flux noise and its paramagnetic temperature dependence
C. M. Quintana, Yu Chen, D. Sank +25
By analyzing the dissipative dynamics of a tunable gap flux qubit, we extract both sides of its two-sided environmental flux noise spectral density over a range of frequencies arou…
Dielectric surface loss in superconducting resonators with flux-trapping holes
B. Chiaro, A. Megrant, A. Dunsworth +18
Surface distributions of two level system (TLS) defects and magnetic vortices are limiting dissipation sources in superconducting quantum circuits. Arrays of flux-trapping holes ar…
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…
Chiral groundstate currents of interacting photons in a synthetic magnetic field
P. Roushan, C. Neill, A. Megrant +22
The intriguing many-body phases of quantum matter arise from the interplay of particle interactions, spatial symmetries, and external fields. Generating these phases in an engineer…
Scalable in-situ qubit calibration during repetitive error detection
J. Kelly, R. Barends, A. G. Fowler +19
We present a method to optimize qubit control parameters during error detection which is compatible with large-scale qubit arrays. We demonstrate our method to optimize single or t…
Ergodic dynamics and thermalization in an isolated quantum system
C. Neill, P. Roushan, M. Fang +19
Statistical mechanics is founded on the assumption that all accessible configurations of a system are equally likely. This requires dynamics that explore all states over time, know…
Scalable Quantum Simulation of Molecular Energies
P. J. J. O'Malley, R. Babbush, I. D. Kivlichan +27
We report the first electronic structure calculation performed on a quantum computer without exponentially costly precompilation. We use a programmable array of superconducting qub…
Digitized adiabatic quantum computing with a superconducting circuit
R. Barends, A. Shabani, L. Lamata +26
A major challenge in quantum computing is to solve general problems with limited physical hardware. Here, we implement digitized adiabatic quantum computing, combining the generali…
Measuring and Suppressing Quantum State Leakage in a Superconducting Qubit
Zijun Chen, Julian Kelly, Chris Quintana +20
Leakage errors occur when a quantum system leaves the two-level qubit subspace. Reducing these errors is critically important for quantum error correction to be viable. To quantify…
Preserving entanglement during weak measurement demonstrated with a violation of the Bell-Leggett-Garg inequality
T. C. White, J. Y. Mutus, J. Dressel +18
Weak measurement has provided new insight into the nature of quantum measurement, by demonstrating the ability to extract average state information without fully projecting the sys…
Traveling wave parametric amplifier with Josephson junctions using minimal resonator phase matching
T. C. White, J. Y. Mutus, I. -C. Hoi +18
Josephson parametric amplifiers have become a critical tool in superconducting device physics due to their high gain and quantum-limited noise. Traveling wave parametric amplifiers…
Digital quantum simulation of fermionic models with a superconducting circuit
R. Barends, L. Lamata, J. Kelly +21
Simulating quantum physics with a device which itself is quantum mechanical, a notion Richard Feynman originated, would be an unparallelled computational resource. However, the uni…
State preservation by repetitive error detection in a superconducting quantum circuit
J. Kelly, R. Barends, A. G. Fowler +19
Quantum computing becomes viable when a quantum state can be preserved from environmentally-induced error. If quantum bits (qubits) are sufficiently reliable, errors are sparse and…
Qubit metrology of ultralow phase noise using randomized benchmarking
P. J. J. O'Malley, J. Kelly, R. Barends +20
A precise measurement of dephasing over a range of timescales is critical for improving quantum gates beyond the error correction threshold. We present a metrological tool, based o…
Characterization and reduction of microfabrication-induced decoherence in superconducting quantum circuits
C. M. Quintana, A. Megrant, Z. Chen +18
Many superconducting qubits are highly sensitive to dielectric loss, making the fabrication of coherent quantum circuits challenging. To elucidate this issue, we characterize the i…
Observation of topological transitions in interacting quantum circuits
P. Roushan, C. Neill, Yu Chen +21
The discovery of topological phases in condensed matter systems has changed the modern conception of phases of matter. The global nature of topological ordering makes these phases…
Rolling quantum dice with a superconducting qubit
R. Barends, J. Kelly, A. Veitia +20
One of the key challenges in quantum information is coherently manipulating the quantum state. However, it is an outstanding question whether control can be realized with low error…
Simulating weak localization using superconducting quantum circuits
Yu Chen, P. Roushan, D. Sank +15
Understanding complex quantum matter presents a central challenge in condensed matter physics. The difficulty lies in the exponential scaling of the Hilbert space with the system s…
Optimal quantum control using randomized benchmarking
J. Kelly, R. Barends, B. Campbell +19
We present a method for optimizing quantum control in experimental systems, using a subset of randomized benchmarking measurements to rapidly infer error. This is demonstrated to i…
Qubit architecture with high coherence and fast tunable coupling
Yu Chen, C. Neill, P. Roushan +20
We introduce a superconducting qubit architecture that combines high-coherence qubits and tunable qubit-qubit coupling. With the ability to set the coupling to zero, we demonstrate…
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…
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…
Catching Shaped Microwave Photons with 99.4% Absorption Efficiency
J. Wenner, Yi Yin, Yu Chen +15
We demonstrate a high efficiency deterministic quantum receiver to convert flying qubits to logic qubits. We employ a superconducting resonator, which is driven with a shaped pulse…