Evan Jeffrey
A5104107642- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Neural Networks and Reservoir Computing
- Advanced Data Storage Technologies
- Quantum many-body systems
- Quantum-Dot Cellular Automata
- Computational Physics and Python Applications
- Theoretical and Computational Physics
- Quantum and electron transport phenomena
- Computational Geometry and Mesh Generation
- Complex Network Analysis Techniques
Google (United States)
2019-2024
Implementation of an error-corrected quantum computer is believed to require a processor with million or more physical qubits, and, in order run such processor, control system similar scale will be required. Such controller need integrated within the cryogenic and close proximity make practical. Here, we present prototype CMOS designed 28-nm bulk process optimized implement 16-word (4-bit) <italic xmlns:mml="http://www.w3.org/1998/Math/MathML"...
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...
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...
Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin 1D Heisenberg model were conjectured to belong Kardar-Parisi-Zhang (KPZ) universality class based on scaling infinite-temperature spin-spin correlation function. a chain 46 superconducting qubits, we study probability distribution, $P(\mathcal{M})$, magnetization transferred across chain's center. The first two moments $P(\mathcal{M})$ show superdiffusive behavior,...
Lattice gauge theories (LGTs) can be employed to understand a wide range of phenomena, from elementary particle scattering in high-energy physics effective descriptions many-body interactions materials. Studying dynamical properties emergent phases challenging as it requires solving problems that are generally beyond perturbative limits. We investigate the dynamics local excitations $\mathbb{Z}_2$ LGT using two-dimensional lattice superconducting qubits. first construct simple variational...
Quantum error correction is essential for bridging the gap between rates of physical devices and extremely low logical required quantum algorithms. Recent error-correction demonstrations on superconducting processors have focused primarily surface code, which offers a high threshold but poses limitations operations. In contrast, color code enables much more efficient logic, although it requires complex stabilizer measurements decoding techniques. Measuring these stabilizers in planar...
A remarkable characteristic of quantum computing is the potential for reliable computation despite faulty qubits. This can be achieved through error correction, which typically implemented by repeatedly applying static syndrome checks, permitting correction logical information. Recently, development time-dynamic approaches to has uncovered new codes and code implementations. In this work, we experimentally demonstrate three implementations surface code, each offering a unique solution...