M. R. Hoffmann
A5073463944- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Quantum many-body systems
- Neural Networks and Reservoir Computing
- Advancements in Semiconductor Devices and Circuit Design
- Quantum Mechanics and Applications
- Neural Networks and Applications
- Semiconductor materials and devices
- Non-Destructive Testing Techniques
- Ultrasonics and Acoustic Wave Propagation
- Topological Materials and Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Random lasers and scattering media
- Algebraic structures and combinatorial models
- Theoretical and Computational Physics
- Research Data Management Practices
- Physics of Superconductivity and Magnetism
- Quantum, superfluid, helium dynamics
- Scientific Computing and Data Management
- Quantum optics and atomic interactions
- Mechanical and Optical Resonators
Google (United States)
2019-2024
University of California, Riverside
2022
Abstract Practical quantum computing will require error rates well below those achievable with physical qubits. Quantum correction 1,2 offers a path to algorithmically relevant by encoding logical qubits within many qubits, for which increasing the number of enhances protection against errors. However, introducing more also increases sources, so density errors must be sufficiently low performance improve code size. Here we report measurement qubit scaling across several sizes, and...
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...
Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for simulation of high-temperature superconductivity or magnetism. Using up 49 superconducting qubits, we prepared low-energy transverse-field Ising model through coupling auxiliary qubits. In one dimension, observed long-range correlations and a ground-state fidelity 0.86 18 qubits at critical point. two dimensions, found mutual information that extends beyond...
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
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...
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...
Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for simulation of high-temperature superconductivity or magnetism. Using up 49 superconducting qubits, we prepared low-energy transverse-field Ising model through coupling auxiliary qubits. In one dimension, observed long-range correlations and a ground-state fidelity 0.86 18 qubits at critical point. two dimensions, found mutual information that extends beyond...
Abstract Measurement has a special role in quantum theory 1 : by collapsing the wavefunction it can enable phenomena such as teleportation 2 and thereby alter "arrow of time" that constrains unitary evolution. When integrated many-body dynamics, measurements lead to emergent patterns information space-time 3-10 go beyond established paradigms for characterizing phases, either or out equilibrium 11-13 . On present-day NISQ processors 14 , experimental realization this physics is challenging...
Understanding how interacting particles approach thermal equilibrium is a major challenge of quantum simulators. Unlocking the full potential such systems toward this goal requires flexible initial state preparation, precise time evolution, and extensive probes for final characterization. We present simulator comprising 69 superconducting qubits which supports both universal gates high-fidelity analog with performance beyond reach classical simulation in cross-entropy benchmarking...
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...
Indistinguishability of particles is a fundamental principle quantum mechanics. For all elementary and quasiparticles observed to date - including fermions, bosons, Abelian anyons this guarantees that the braiding identical leaves system unchanged. However, in two spatial dimensions, an intriguing possibility exists: non-Abelian causes rotations space topologically degenerate wavefunctions. Hence, it can change observables without violating indistinguishability. Despite well developed...
Measurement has a special role in quantum theory: by collapsing the wavefunction it can enable phenomena such as teleportation and thereby alter "arrow of time" that constrains unitary evolution. When integrated many-body dynamics, measurements lead to emergent patterns information space-time go beyond established paradigms for characterizing phases, either or out equilibrium. On present-day NISQ processors, experimental realization this physics is challenging due noise, hardware...
One of the most challenging problems in computational study localization quantum manybody systems is to capture effects rare events, which requires sampling over exponentially many disorder realizations. We implement an efficient procedure on a processor, leveraging parallelism, efficiently sample all observe without many-body dynamics one and two dimensions: perturbations do not diffuse even though both generator evolution initial states are fully translationally invariant. The strength as...
The rise of Generative AI (GenAI) brings about transformative potential across sectors, but its dual-use nature also amplifies risks. Governments globally are grappling with the challenge regulating GenAI, balancing innovation against safety. China, United States (US), and European Union (EU) at forefront initiatives like Management Algorithmic Recommendations, Executive Order, Act, respectively. However, rapid evolution GenAI capabilities often outpaces development comprehensive safety...
Abstract An important measure of the development quantum computing platforms has been simulation increasingly complex physical systems [1–3]. Prior to fault-tolerant computing, robust error mitigation strategies are necessary continue this growth [4–11]. Here, we study within seniority-zero electron pairing subspace, which affords both a computational stepping stone fully correlated model [12–17], and an opportunity validate recently introduced “purification-based” error-mitigation [8–10]....