Explanipedia

Observation of separated dynamics of charge and spin in the Fermi-Hubbard model Open

Frank Arute, Kunal Arya, Ryan Babbush, Dave Bacon, Joseph C. Bardin , et al. · 2020

Strongly correlated quantum systems give rise to many exotic physical phenomena, including high-temperature superconductivity. Simulating these systems on quantum computers may avoid the prohibitively high computational cost incurred in cl…

Demonstrating a Continuous Set of Two-qubit Gates for Near-term Quantum Algorithms Open

Brooks Foxen, Charles Neill, A. Dunsworth, P. Roushan, B. Chiaro , et al. · 2020

Quantum algorithms offer a dramatic speedup for computational problems in material science and chemistry. However, any near-term realizations of these algorithms will need to be optimized to fit within the finite resources offered by exist…

Diabatic Gates for Frequency-Tunable Superconducting Qubits Open

R. Barends, Chris Quintana, A. G. Petukhov, Yu Chen, Dvir Kafri , et al. · 2019

We demonstrate diabatic two-qubit gates with Pauli error rates down to 4.3(2)×10^{-3} in as fast as 18 ns using frequency-tunable superconducting qubits. This is achieved by synchronizing the entangling parameters with minima in the leakag…

Growth and preservation of entanglement in a many-body localized system Open

B. Chiaro, Charles Neill, Annabelle Bohrdt, Michele Filippone, Frank Arute , et al. · 2019

In non-interacting systems disorder leads to Anderson localization, where particle diffusion and entanglement propagation are absent. Interactions between the constituent particles modify this picture, leading to a many-body localized (MBL…

Fluctuations of Energy-Relaxation Times in Superconducting Qubits Open

Paul V. Klimov, J. Kelly, Z. Chen, M. Neeley, A. Megrant , et al. · 2018

Superconducting qubits are an attractive platform for quantum computing since they have demonstrated high-fidelity quantum gates and extensibility to modest system sizes. Nonetheless, an outstanding challenge is stabilizing their energy-re…

A blueprint for demonstrating quantum supremacy with superconducting qubits Open

C. Neill, P. Roushan, Kostyantyn Kechedzhi, Sergio Boixo, Sergei V. Isakov , et al. · 2018

Scaling up to supremacy Quantum information scientists are getting closer to building a quantum computer that can perform calculations that a classical computer cannot. It has been estimated that such a computer would need around 50 qubits…

Spectroscopic signatures of localization with interacting photons in superconducting qubits Open

P. Roushan, C. Neill, Jirawat Tangpanitanon, V. M. Bastidas, A. Megrant , et al. · 2017

Putting photons to work Interacting quantum particles can behave in peculiar ways. To understand that behavior, physicists have turned to quantum simulation, in which a tunable and clean system can be monitored as it evolves under the infl…

Qubit compatible superconducting interconnects Open

Brooks Foxen, J. Mutus, Erik Lucero, R. Graff, A. Megrant , et al. · 2017

We present a fabrication process for fully superconducting interconnects compatible with superconducting qubit technology. These interconnects allow for the 3D integration of quantum circuits without introducing lossy amorphous dielectrics…

Spectral signatures of many-body localization with interacting photons Open

P. Roushan, C. Neill, Jirawat Tangpanitanon, V. M. Bastidas, A. Megrant , et al. · 2017

Statistical mechanics is founded on the assumption that a system can reach thermal equilibrium, regardless of the starting state. Interactions between particles facilitate thermalization, but, can interacting systems always equilibrate reg…

Characterization and reduction of capacitive loss induced by sub-micron Josephson junction fabrication in superconducting qubits Open

A. Dunsworth, A. Megrant, Chris Quintana, Zijun Chen, R. Barends , et al. · 2017

Josephson junctions form the essential non-linearity for almost all superconducting qubits. The junction is formed when two superconducting electrodes come within ∼1 nm of each other. Although the capacitance of these electrodes is a small…

Observation of Classical-Quantum Crossover of Flux Noise and Its Paramagnetic Temperature Dependence Open

Claudia Quintana, Yu Chen, D. Sank, A. G. Petukhov, T. White , et al. · 2017

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 around 2k_{B}T/h≈1 GHz, allowing for the observation of a class…

Measurement-Induced State Transitions in a Superconducting Qubit: Beyond the Rotating Wave Approximation Open

D. Sank, Zijun Chen, Mostafa Khezri, J. Kelly, R. Barends , et al. · 2016

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 that such measurements can induce state transitions in the…

Scalable<i>in situ</i>qubit calibration during repetitive error detection Open

J. Kelly, R. Barends, Austin G. Fowler, A. Megrant, E. Jeffrey , et al. · 2016

We present a method to optimize qubit control parameters during error\ndetection which is compatible with large-scale qubit arrays. We demonstrate our\nmethod to optimize single or two-qubit gates in parallel on a nine-qubit\nsystem. Addit…

Ergodic dynamics and thermalization in an isolated quantum system Open

C. Neill, P. Roushan, M.T.C. Fang, Yu Chen, Michael Kolodrubetz , et al. · 2016

Digitized adiabatic quantum computing with a superconducting circuit Open

R. Barends, Alireza Shabani, Lucas Lamata, J. Kelly, Antonio Mezzacapo , et al. · 2016

Scalable in-situ qubit calibration during repetitive error detection Open

J. Kelly, R. Barends, Austin G. Fowler, J. Mutus, B. Campbell , et al. · 2016

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 two-qubit gates in parallel on a nine-qubit system. Addition…

Preserving entanglement during weak measurement demonstrated with a violation of the Bell–Leggett–Garg inequality Open

T. White, J. Mutus, Justin Dressel, J. Kelly, R. Barends , et al. · 2016

Measuring and Suppressing Quantum State Leakage in a Superconducting Qubit Open

Zijun Chen, J. Kelly, Chris Quintana, R. Barends, B. Campbell , et al. · 2016

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 leakage errors, we use randomized benchmarking in conjunct…

Digital quantum simulation of fermionic models with a superconducting circuit Open

R. Barends, Lucas Lamata, J. Kelly, Laura García-Álvarez, Austin G. Fowler , et al. · 2015

Traveling wave parametric amplifier with Josephson junctions using minimal resonator phase matching Open

T. White, J. Mutus, I.-C. Hoi, R. Barends, B. Campbell , et al. · 2015

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 (TWPAs) promise similar noise performance, while allowing …

Qubit Metrology of Ultralow Phase Noise Using Randomized Benchmarking Open

P. O’Malley, J. Kelly, R. Barends, B. Campbell, Yanbin Chen , et al. · 2015

A precise measurement of dephasing over a range of timescales is critical for\nimproving quantum gates beyond the error correction threshold. We present a\nmetrological tool, based on randomized benchmarking, capable of greatly\nincreasing…

Violating the Bell-Leggett-Garg inequality with weak measurement of an entangled state Open

Justin Dressel, J. Kelly, R. Barends, Evan Jerey, D. Sank , et al. · 2015

Since the inception of quantum mechanics, its validity as a complete description of reality has been challenged due to predictions that defy classical intuition. For many years it was unclear whether predictions like entanglement and proje…

Traveling wave parametric amplifier with Josephson junctions using minimal resonator phase matching Open

T. White, J. Mutus, I.-C. Hoi, R. Barends, B. Campbell , et al. · 2015

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 (TWPAs) promise similar noise performance while allowing f…

State preservation by repetitive error detection in a superconducting quantum circuit Open

J. Kelly, R. Barends, Austin G. Fowler, A. Megrant, E. Jeffrey , et al. · 2015

A. Vainsencher YOU? Author Swipe