A5028266479- Quantum Information and Cryptography
- Quantum Computing Algorithms and Architecture
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum and electron transport phenomena
- Quantum optics and atomic interactions
- Quantum Mechanics and Applications
- Atomic and Molecular Physics
- Advanced Frequency and Time Standards
- Distributed and Parallel Computing Systems
- Laser-Matter Interactions and Applications
- Advanced Data Storage Technologies
- Orbital Angular Momentum in Optics
- Scientific Computing and Data Management
- Quantum-Dot Cellular Automata
- Agronomic Practices and Intercropping Systems
- Molecular Junctions and Nanostructures
- Parallel Computing and Optimization Techniques
- Photonic and Optical Devices
- Cloud Computing and Resource Management
- Botany and Geology in Latin America and Caribbean
- Mass Spectrometry Techniques and Applications
- Atomic and Subatomic Physics Research
- Analytical Chemistry and Sensors
- Laser-induced spectroscopy and plasma
- Experimental and Theoretical Physics Studies
University of Oxford
2014-2024
Science Oxford
2022-2023
DEVCOM Army Research Laboratory
2022
Improvement Service
2020
Environmental Protection Agency
2019
We demonstrate laser-driven two-qubit and single-qubit logic gates with respective fidelities 99.9(1)% 99.9934(3)%, significantly above the ≈99% minimum threshold level required for fault-tolerant quantum computation, using qubits stored in hyperfine ground states of calcium-43 ions held a room-temperature trap. study speed-fidelity trade-off gate, gate times between 3.8 μs 520 μs, develop theoretical error model which is consistent data allows us to identify principal technical sources infidelity.
We implement all single-qubit operations with fidelities significantly above the minimum threshold required for fault-tolerant quantum computing, using a trapped-ion qubit stored in hyperfine "atomic clock" states of ^{43}Ca^{+}. measure combined state preparation and single-shot readout fidelity 99.93%, memory coherence time T_{2}^{*}=50 sec, an average gate 99.9999%. These results are achieved room-temperature microfabricated surface trap, without use magnetic field shielding or dynamic...
We demonstrate a two-qubit logic gate driven by near-field microwaves in room-temperature microfabricated ion trap. measure fidelity of 99.7(1)\%, which is above the minimum threshold required for fault-tolerant quantum computing. The applied directly to $^{43}$Ca$^+$ "atomic clock" qubits (coherence time $T_2^*\approx 50\,\mathrm{s}$) using microwave magnetic field gradient produced trap electrode. introduce dynamically-decoupled method, stabilizes against fluctuating a.c.\ Zeeman shifts...
Atomic physics experiments commonly use millitesla-scale magnetic fields to provide a quantization axis. As atomic transition frequencies depend on the magnitude of this field, many require stable absolute field. Most setups electromagnets, which power supply stability not usually met by commercially available units. We demonstrate stabilization field 14.6 mT 4.3 nT rms noise (0.29 ppm), compared >100 without any stabilization. The is measured using field-dependent hyperfine in single 43Ca+...
Laser cleaning of the electrodes in a planar micro-fabricated ion trap has been attempted using ns pulses from tripled Nd:YAG laser at 355 nm. The effect several energy density levels tested by measuring heating rate single 40Ca+ trapped as function its secular frequency ωz. A reduction electric-field noise spectral ∼50% observed and change dependence also noticed. This is first reported experiment where 'anomalous heating' phenomenon reduced removing source opposed to reducing thermal...
Microwave-driven logic is a promising alternative to laser control in scaling trapped-ion based quantum processors. We implement Mølmer-Sørensen two-qubit gates on <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msup><a:mrow/><a:mn>43</a:mn></a:msup><a:msup><a:mrow><a:mi>Ca</a:mi></a:mrow><a:mo>+</a:mo></a:msup></a:math> hyperfine clock qubits cryogenic <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mo>(</b:mo><b:mo>≈</b:mo><b:mn>25</b:mn><b:mo> </b:mo><b:mi...
We present a new method for coherent control of trapped ion qubits in separate interaction regions multizone trap by simultaneously applying an electric field and spin-dependent gradient. Both the phase amplitude effective single-qubit rotation depend on field, which can be localized to each zone. demonstrate this single using both laser-based magnetic-field gradients surface-electrode trap, measure localization field.
Individual addressing of qubits is essential for scalable quantum computation. Spatial allows unlimited numbers to share the same frequency, while enabling arbitrary parallel operations. We demonstrate long-lived $^{43}\mathrm{Ca}^{+}$ ``atomic clock'' held in separate zones ($960\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\text{m}$ apart) a microfabricated surface trap with integrated microwave electrodes. Such could form part ``quantum charge-coupled device'' architecture large-scale...
We describe the design, fabrication and testing of a surface-electrode ion trap, which incorporates microwave waveguides, resonators coupling elements for manipulation trapped qubits using near-field microwaves. The trap is optimised to give large field gradient allow state-dependent ions' motional degrees freedom, key multiqubit entanglement. near centre characterised by driving hyperfine transitions in single laser-cooled 43Ca+ ion.
Robust qubit memory is essential for quantum computing, both near-term devices operating without error correction, and the long-term goal of a fault-tolerant processor. We directly measure ${\ensuremath{\epsilon}}_{m}$ $^{43}{\mathrm{Ca}}^{+}$ trapped-ion in small-error regime find ${\ensuremath{\epsilon}}_{m}<{10}^{\ensuremath{-}4}$ storage times $t\ensuremath{\lesssim}50\text{ }\text{ }\mathrm{ms}$. This exceeds gate or measurement by three orders magnitude. Using randomized benchmarking,...
Abstract We report the design, fabrication, and characterization of a cryogenic ion trap system for implementation quantum logic driven by near-field microwaves. The incorporates an on-chip microwave resonator with electrode geometry designed to null field component that couples directly qubit, while giving large gradient driving entangling gates. map using single 43 Ca + ion, measure trapping lifetime motional mode heating rates one two ions.
Sinara is a control system dedicated to quantum applications. It based on industrial standards and consists of over 50 modules. The hardware controlled by ARTIQ, which provides high-level programming language.
The central challenge of quantum computing is implementing high-fidelity gates at scale. However, many existing approaches to qubit control suffer from a scale-performance trade-off, impeding progress towards the creation useful devices. Here, we present vision for an electronically controlled trapped-ion computer that alleviates this bottleneck. Our architecture utilizes shared current-carrying traces and local tuning electrodes in microfabricated chip perform with low noise crosstalk...
We describe Urukul, a frequency synthesizer based on direct digital synthesis (DDS), optimized for wave generate control in atomic, molecular and optical (AMO) physics experiments.The Urukul module is part of the Sinara family modular, open-source hardware designed ARTIQ quantum operating system.The has 4-channel, sub-Hz resolution, controlled phase steps accurate output amplitude control.The available two population variants.This paper presents construction obtained characteristics.
We demonstrate simple and robust methods for Doppler cooling obtaining high fluorescence from trapped 43Ca+ ions at a magnetic field of 146 Gauss. This gives access to magnetic-field-independent 'atomic clock' qubit transition within the ground level hyperfine structure ion, but also causes complex internal 64 states relevant be spread over many times atomic line-width. Using time-dependent optical Bloch equation simulation system we develop scheme Doppler-cool ion on two-photon dark...
One of the most formidable challenges scaling up quantum computers is that control-signal delivery. In this Paper, we present recent results on integrated and scalable control trapped-ion qubits at Oxford Ionics.
Microwave-driven logic is a promising alternative to laser control in scaling trapped-ion based quantum processors. However, such electronic gates have yet match the speed offered by their laser-driven counterparts. Here, we implement M{\o}lmer-S{\o}rensen two-qubit on $^{43}\text{Ca}^+$ hyperfine clock qubits cryogenic ($\approx25~\text{K}$) surface trap, driven near-field microwaves. We achieve gate durations of $154~\mu\text{s}$ (with $1.0(2)\%$ error) and $331~\mu\text{s}$ ($0.5(1)\%$...
We report precision measurements of the nuclear magnetic moment $^{43}\mathrm{Ca}^{+}$, made by microwave spectroscopy $4s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}|F=4,\phantom{\rule{0.28em}{0ex}}M=0\ensuremath{\rangle}\ensuremath{\rightarrow}|F=3,\phantom{\rule{0.28em}{0ex}}M=1\ensuremath{\rangle}$ ground level hyperfine clock transition at a field $\ensuremath{\approx}146\phantom{\rule{0.16em}{0ex}}\mathrm{G}$, using single laser-cooled ion in Paul trap. measure clock-transition frequency...
I will describe recent experimental work at Oxford on implementing elementary one- and two-qubit operations with the high fidelities (99.9% or more) required for implementation of quantum error correction, using trapped-ion "atomic clock" qubits.