Alexis Morvan
A5074212158- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Advancements in Semiconductor Devices and Circuit Design
- Physics of Superconductivity and Magnetism
- Quantum many-body systems
- Cold Atom Physics and Bose-Einstein Condensates
- Neural Networks and Reservoir Computing
- Quantum optics and atomic interactions
- Topological Materials and Phenomena
- Parallel Computing and Optimization Techniques
- Quantum Mechanics and Applications
- Semiconductor materials and devices
- Advanced Data Storage Technologies
- Ultrasonics and Acoustic Wave Propagation
- Photonic Crystals and Applications
- Quantum-Dot Cellular Automata
- Theoretical and Computational Physics
- Neural Networks and Applications
- Mechanical and Optical Resonators
- Non-Destructive Testing Techniques
- Superconducting and THz Device Technology
- Advanced MEMS and NEMS Technologies
- Gyrotron and Vacuum Electronics Research
- Silicon and Solar Cell Technologies
Google (United States)
2022-2025
Lawrence Berkeley National Laboratory
2020-2024
Centre National de la Recherche Scientifique
2019-2022
Université Paris-Saclay
2019-2022
Laboratoire de physique des Solides
2018-2022
University of California, Berkeley
2021-2022
University of California, Riverside
2022
IFP Énergies nouvelles
2019
Université Paris-Sud
2019
Synchrotron soleil
2013
Ternary quantum processors offer significant potential computational advantages over conventional qubit technologies, leveraging the encoding and processing of information in qutrits (three-level systems). To evaluate compare performance such emerging hardware it is essential to have robust benchmarking methods suitable for a higher-dimensional Hilbert space. We demonstrate extensions industry standard randomized (RB) protocols, developed used extensively qubits, ternary logic. Using...
Ternary quantum information processing in superconducting devices poses a promising alternative to its more popular binary counterpart through larger, connected computational spaces and proposed advantages simulation error correction. Although generally operated as qubits, transmons have readily addressable higher levels, making them natural candidates for operation three-level systems (qutrits). Recent works transmon realized high fidelity single qutrit operation. Nonetheless, effectively...
Indistinguishability of particles is a fundamental principle quantum mechanics
Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin one-dimensional Heisenberg model were conjectured as to belong Kardar-Parisi-Zhang (KPZ) universality class based on scaling infinite-temperature spin-spin correlation function. a chain 46 superconducting qubits, we studied probability distribution magnetization transferred across chain's center, [Formula: see text]. The first two moments text] show superdiffusive...
Undesired coupling to the surrounding environment destroys long-range correlations in quantum processors and hinders coherent evolution nominally available computational space. This noise is an outstanding challenge when leveraging computation power of near-term
We have observed the unconventional photon blockade effect for microwave photons using two coupled superconducting resonators. As opposed to conventional blockade, only weakly nonlinear resonators are required. The is revealed through measurements of second order correlation function g^{(2)}(t) field inside one lowest measured value g^{(2)}(0) 0.4 a resonator population approximately 10^{-2} photons. time evolution exhibits an oscillatory behavior, which characteristic blockade.
The successful implementation of algorithms on quantum processors relies the accurate control bits (qubits) to perform logic gate operations. In this era noisy intermediate-scale (NISQ) computing, systematic miscalibrations, drift, and crosstalk in qubits can lead a coherent form error that has no classical analog. Coherent errors severely limit performance an unpredictable manner, mitigating their impact is necessary for realizing reliable computations. Moreover, average rates measured by...
Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the one-dimensional kicked Ising model which exhibits non-local Majorana edge modes (MEMs) with $\mathbb{Z}_2$ parity symmetry. Remarkably, find that any multi-qubit Pauli operator overlapping MEMs uniform late-time decay rate comparable to single-qubit relaxation...
Systems of correlated particles appear in many fields modern science and represent some the most intractable computational problems nature. The challenge these systems arises when interactions become comparable to other energy scales, which makes state each particle depend on all particles1. lack general solutions for three-body problem acceptable theory strongly electrons shows that our understanding fades number or interaction strength increases. One hallmarks interacting is formation...
The technological development of hardware heading toward universal fault-tolerant quantum computation requires a large-scale processing unit with high performance. While fluxonium qubits are promising coherence and large anharmonicity, their scalability has not been systematically explored. In this work, we propose superconducting information processor based on compact high-coherence fluxoniums suppressed crosstalk, reduced design complexity, improved operational efficiency, high-fidelity...
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 matched to 50 Ω environment with Klopfenstein-taper impedance transformer and achieves bandwidth 250–300 MHz input saturation powers up −95 dBm at 20 dB gain. A 54-qubit Sycamore processor was used benchmark these devices, providing calibration for readout power, estimation added noise, platform comparison against standard...
Using near-term quantum computers to achieve a advantage requires efficient strategies improve the performance of noisy devices presently available. We develop and experimentally validate two error mitigation protocols named ``Noiseless Output Extrapolation" ``Pauli Error Cancellation" that can drastically enhance circuits composed cycles gates. By combining popular such as probabilistic cancellation noise amplification with reconstruction methods, our mitigate wide range processes do not...
The theory of quantum information provides a common language which links disciplines ranging from cosmology to condensed-matter physics. For example, the delocalization in strongly-interacting many-body systems, known as scrambling, has recently begun unite our understanding black hole dynamics, transport exotic non-Fermi liquids, and analogs chaos. To date, verified experimental implementations scrambling have dealt only with systems comprised two-level qubits. Higher-dimensional however,...
Fixed-frequency superconducting quantum processors are one of the most mature computing architectures with high-coherence qubits and simple controls. However, high-fidelity multi-qubit gates pose tight requirements on individual qubit frequencies in these , constraints difficult to satisfy when constructing larger due large dispersion fabrication Josephson junctions. In this article, we propose a mixed-integer-programming-based optimization approach that determines maximize yield processors....
Quantum bits, or qubits, are an example of coherent circuits envisioned for next-generation computers and detectors. A robust superconducting qubit with a lifetime $O$(100 $\mu$s) is the transmon: Josephson junction functioning as non-linear inductor shunted capacitor to form anharmonic oscillator. In complex device many such transmons, precise control over each frequency often required, thus variations area tunnel barrier thickness must be sufficiently minimized achieve optimal performance...
As superconducting quantum processors increase in complexity, techniques to overcome constraints on frequency crowding are needed. The recently developed method of laser-annealing provides an effective post-fabrication adjust the qubits. Here, we present automated apparatus based conventional microscopy components and demonstrate preservation highly coherent transmons. In addition, perform noise spectroscopy investigate change defect features, particular, two-level system defects, after...
Using near-term quantum computers to achieve a advantage requires efficient strategies improve the performance of noisy devices presently available. We develop and experimentally validate two error mitigation protocols named "Noiseless Output Extrapolation" "Pauli Error Cancellation" that can drastically enhance circuits composed cycles gates. By combining popular such as probabilistic cancellation noise amplification with reconstruction methods, our mitigate wide range processes do not...
Recent progress in noisy intermediate-scale quantum (NISQ) hardware shows that devices may be able to tackle complex problems even without error correction. However, coherent errors due the increased complexity of these is an outstanding issue. They can accumulate through a circuit, making their impact on algorithms hard predict and mitigate. Iterative like imaginary time evolution are susceptible errors. This article presents combination both noise tailoring using randomized compiling...
Generating high-fidelity, tunable entanglement between qubits is crucial for realizing gate-based quantum computation. In superconducting circuits, interactions are often implemented using flux-tunable or coupling elements, adding control complexity and noise sources. Here, we realize a ZZ interaction two transmon with fixed frequencies coupling, induced by driving both transmons off resonantly. We show over 1 order of magnitude larger than the static change sign interaction, enabling...
We demonstrate a new approach to dissipation engineering in microwave quantum optics. For single mode, usually corresponds jumps, where photons are lost one by one. Here, we able tune the minimal number of per jump be two (or more) with simple dc voltage. As consequence, different states experience dissipation. Causality implies that must also energy shifts. Our measurements these Lamb shifts good agreement predictions Kramers-Kronig relations for regime highly non-linear bath coupling. This...
Leakage of quantum information out computational states into higher energy represents a major challenge in the pursuit error correction (QEC). In QEC circuit, leakage builds over time and spreads through multi-qubit interactions. This leads to correlated errors that degrade exponential suppression logical with scale, challenging feasibility as path towards fault-tolerant computation. Here, we demonstrate execution distance-3 surface code distance-21 bit-flip on Sycamore processor where is...
High-throughput synthesis combined with a surface organometallic (coordination) chemistry approach is used to prepare in systematic way series of 40 metal-promoted (Me)–MoS2 active phases supported on amorphous silica alumina various Me/Mo ratios (0–0.5). The intrinsic catalytic activity model reaction, namely, toluene hydrogenation, evaluated also by high-throughput method shows well-marked optimal ratio corresponding an improved respect the MoS2 reference for Me = Fe, Co, and Ni. In...