A5071477014- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Quantum optics and atomic interactions
- Cold Atom Physics and Bose-Einstein Condensates
- Diamond and Carbon-based Materials Research
- Mechanical and Optical Resonators
- Quantum Computing Algorithms and Architecture
- Semiconductor Quantum Structures and Devices
- Advanced Fiber Laser Technologies
- Atomic and Subatomic Physics Research
- Force Microscopy Techniques and Applications
- Quantum many-body systems
- Spectroscopy and Quantum Chemical Studies
- Neural Networks and Reservoir Computing
- Laser-Matter Interactions and Applications
- Advanced Thermodynamics and Statistical Mechanics
- Molecular Junctions and Nanostructures
- Advanced Surface Polishing Techniques
- Metal and Thin Film Mechanics
- Material Dynamics and Properties
- Electronic and Structural Properties of Oxides
- Thermal properties of materials
- Quantum Electrodynamics and Casimir Effect
- Magnetic properties of thin films
- Laser-Ablation Synthesis of Nanoparticles
University of Cambridge
2017-2025
University of Oxford
2022-2023
Science Oxford
2023
Massachusetts Institute of Technology
2013-2018
Cavendish Hospital
2017
MIT-Harvard Center for Ultracold Atoms
2013-2016
University of Waterloo
2011
University of Ottawa
2009
Solid-state quantum emitters that couple coherent optical transitions to long-lived spin qubits are essential for networks. Here we report on the and properties of individual tin-vacancy (SnV) centers in diamond nanostructures. Through cryogenic magneto-optical spectroscopy, verify inversion-symmetric electronic structure SnV, identify spin-conserving spin-flipping transitions, characterize transition linewidths, measure electron lifetimes, evaluate dephasing time. We find consistent with...
Friction between ordered, atomically smooth surfaces at the nanoscale (nanofriction) is often governed by stick-slip processes. To test long-standing atomistic models of such processes, we implement a synthetic nanofriction interface laser-cooled Coulomb crystal individually addressable ions as moving object, and periodic light-field potential substrate. We show that friction can be tuned from maximal to nearly frictionless via arrangement relative By varying ion number, also this strong...
Group-IV color centers in diamond are a promising light-matter interface for quantum networking devices. The negatively charged tin-vacancy center (SnV) is particularly interesting, as its large spin-orbit coupling offers strong protection against phonon dephasing and robust cyclicity of optical transitions towards spin-photon entanglement schemes. Here, we demonstrate multi-axis coherent control the SnV spin qubit via an all-optical stimulated Raman drive between ground excited states. We...
Tin-vacancy centers in diamond are promising spin-photon interfaces owing to their high quantum efficiency, large Debye-Waller factor, and compatibility with photonic nanostructuring. Benchmarking single-photon indistinguishability is a key challenge for future applications. Here, we report the generation of single photons 99.7_{-2.5}^{+0.3}% purity 63(9)% from resonantly excited tin-vacancy center single-mode waveguide. We obtain control optical transition 1.71(1)-ns-long π pulses 77.1(8)%...
Coherent excitation of an ensemble quantum objects underpins many-body phenomena and offers the opportunity to realize a memory that stores information. Thus far, deterministic coherent interface between spin qubit such has remained elusive. In this study, we first used electron cool mesoscopic nuclear semiconductor dot sideband-resolved regime. We then implemented all-optical approach access individual quantized electronic-nuclear transitions. Lastly, performed optical rotations single...
Short-term synaptic plasticity (STP) can significantly alter the amplitudes of responses in ways that depend on presynaptic history. Thus, it is widely assumed STP acts as a filter for specific patterns inputs, and result play key roles neuronal information processing. To evaluate this assumption directly quantify effects transmission, we consider population independent inputs to model neuron. We show using standard theoretic approaches changes response amplitude resulting from interact with...
Quantization of energy is a quintessential characteristic quantum systems. Here we analyze its effects on the operation Otto cycle heat machines and show that quantization alone may alter increase machine performance in terms output power, efficiency, even mode. Our results demonstrate thermodynamics enable realization classically inconceivable machines, such as those with an incompressible working fluid. We propose to measure these experimentally using laser-cooled trapped ion microscopic machine.
Coupling a qubit coherently to an ensemble is the basis for collective quantum memories. A single driven electron in dot can deterministically excite low-energy modes of nuclear spin presence lattice strain. We propose gate state transfer between this central and these excitations-spin waves-in strong magnetic field, where coherence time long. develop microscopic theory capable calculating exact evolution strained electron-nuclear system. With this, we evaluate operation storage show that...
A controlled quantum system can alter its environment by feedback, leading to reduced-entropy states of the and improved coherence. Here, using a quantum-dot electron spin as control probe, we prepare nuclei under feedback coherent population trapping observe their evolution from thermal state, with immediate consequence extended qubit Via Ramsey interferometry on spin, directly access nuclear distribution following preparation measure emergence decay correlations within ensemble. Under...
A central spin qubit interacting coherently with an ensemble of proximal spins can be used to engineer entangled collective states or a multiqubit register. Making full use this many-body platform requires tuning the interaction between and its GaAs quantum dots offer model realization system where electron interacts multiple ensembles <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mo>∼</a:mo><a:msup><a:mn>10</a:mn><a:mn>4</a:mn></a:msup></a:math> nuclear spins. In...
We report the localization of an ion by a one-dimensional optical lattice in presence applied external force. The is confined radially radio frequency trap and axially combined electrostatic optical-lattice potential. Using resolved Raman sideband technique, one or several ions are cooled to mean vibrational number <n>=(0.1±0.1) along lattice. measure average position periodically driven with resolution down λ/40, demonstrate single site for up 10 ms. This opens new possibilities studying...
Photonic cluster states are a powerful resource for measurement-based quantum computing and loss-tolerant communication. Proposals to generate multi-dimensional lattice have identified coupled spin-photon interfaces, spin-ancilla systems, optical feedback mechanisms as potential schemes. Following these, we propose the generation of using single, efficient interface strongly nuclear register. Our scheme makes use contact hyperfine interaction enable universal gates between spin local...
We present a novel hybrid system where an optical cavity is integrated with microfabricated planar-electrode ion trap. The trap electrodes produce tunable periodic potential allowing the trapping of up to 50 separate chains spaced by 160 $\mu$m along axis. Each chain can contain 20 individually addressable Yb\textsuperscript{+} ions coupled mode. demonstrate deterministic distribution between sites electrostatic and control ion-cavity coupling. measured strength this coupling should allow...
High-finesse optical cavities placed under vacuum are foundational platforms in quantum information science with photons and atoms. We study the vacuum-induced degradation of high-finesse mirror coatings composed SiO₂-Ta₂O₅ dielectric stacks, present methods to protect these recover their initial low loss levels. For separate reflectivities centered at 370 nm 422 nm, a continuous increase occurs if surface-layer coating is made Ta₂O₅, while it does not occur SiO₂. The incurred can be...
This Roadmap provides an overview of the critical role materials in exploiting spin and topology for next-generation quantum technologies including computing, sensing, information storage networking devices. We explore key systems that support topological phenomena discuss their figures merit. Spin topology-based have several advantages over classical, charged-based counterparts, non-volatility, faster data processing speeds, higher integration densities lower power consumption. main...
Abstract Quantum control of solid-state spin qubits typically involves pulses in the microwave domain, drawing from well-developed toolbox magnetic resonance spectroscopy. Driving a by optical means offers high-speed alternative, which presence limited coherence makes it preferred approach for high-fidelity quantum control. Bringing full versatility to domain requires phase and amplitude fields. Here, we imprint programmable sequence onto laser field perform electron semiconductor dot via...
This paper reports the observation of a structural phase transition crystal trapped ions in an optical lattice as captured by appearance kink defect. The authors observe stick-slip dynamics chain atom and find that critical degree incommensurability is required for kinks to form.
Controllable quantum many-body systems are platforms for fundamental investigations into the nature of entanglement and promise to deliver computational speed-up a broad class algorithms simulations. In particular, engineering within dense spin ensemble can turn it robust memory or platform. Recent experimental progress in central-spin motivates design that use qubit as convenient proxy ensemble. Here we propose protocol uses central initialize two ensembles pure antipolarized state from...