Publications (20)
A blueprint for demonstrating quantum supremacy with superconducting qubits
C. Neill, P. Roushan, K. Kechedzhi +25
Fundamental questions in chemistry and physics may never be answered due to the exponential complexity of the underlying quantum phenomena. A desire to overcome this challenge has…
Spectral signatures of many-body localization with interacting photons
P. Roushan, C. Neill, J. Tangpanitanon +23
Statistical mechanics is founded on the assumption that a system can reach thermal equilibrium, regardless of the starting state. Interactions between particles facilitate thermali…
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…
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…
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…
Disentangling the sources of ionizing radiation in superconducting qubits
L. Cardani, I. Colantoni, A. Cruciani +27
Radioactivity was recently discovered as a source of decoherence and correlated errors for the real-world implementation of superconducting quantum processors. In this work, we mea…
Removing leakage-induced correlated errors in superconducting quantum error correction
M. McEwen, D. Kafri, Z. Chen +48
Quantum computing can become scalable through error correction, but logical error rates only decrease with system size when physical errors are sufficiently uncorrelated. During co…
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…
Direct measurement of non-local interactions in the many-body localized phase
B. Chiaro, C. Neill, A. Bohrdt +58
The interplay of interactions and strong disorder can lead to an exotic quantum many-body localized (MBL) phase. Beyond the absence of transport, the MBL phase has distinctive sign…
Accurately computing electronic properties of a quantum ring
C. Neill, T. McCourt, X. Mi +89
A promising approach to study condensed-matter systems is to simulate them on an engineered quantum platform. However, achieving the accuracy needed to outperform classical methods…
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…
Visualizing heterogeneous dipole fields by terahertz light coupling in individual nano-junctions used in transmon qubits
R. H. J. Kim, J. M. Park, S. Haeuser +12
The fundamental challenge underlying superconducting quantum computing is to characterize heterogeneity and disorder in the underlying quantum circuits. These nonuniform distributi…
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…
Logic gates at the surface code threshold: Superconducting qubits poised for fault-tolerant quantum computing
R. Barends, J. Kelly, A. Megrant +19
A quantum computer can solve hard problems - such as prime factoring, database searching, and quantum simulation - at the cost of needing to protect fragile quantum states from err…
Diabatic gates for frequency-tunable superconducting qubits
R. Barends, C. M. Quintana, A. G. Petukhov +43
We demonstrate diabatic two-qubit gates with Pauli error rates down to in as fast as 18 ns using frequency-tunable superconducting qubits. This is achieved by…
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…
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…
Coherent Josephson qubit suitable for scalable quantum integrated circuits
R. Barends, J. Kelly, A. Megrant +13
We demonstrate a planar, tunable superconducting qubit with energy relaxation times up to 44 microseconds. This is achieved by using a geometry designed to both minimize radiative…
Realizing topologically ordered states on a quantum processor
K. J. Satzinger, Y. Liu, A. Smith +95
The discovery of topological order has revolutionized the understanding of quantum matter in modern physics and provided the theoretical foundation for many quantum error correctin…
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…