A5052134684- Quantum Information and Cryptography
- Diamond and Carbon-based Materials Research
- Quantum and electron transport phenomena
- Semiconductor Quantum Structures and Devices
- Quantum optics and atomic interactions
- Advanced Fiber Laser Technologies
- Mechanical and Optical Resonators
- Force Microscopy Techniques and Applications
- 2D Materials and Applications
- Photonic and Optical Devices
- Quantum Mechanics and Applications
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- Quantum Computing Algorithms and Architecture
- Perovskite Materials and Applications
- Quantum Dots Synthesis And Properties
- Molecular Junctions and Nanostructures
- Atomic and Subatomic Physics Research
- Semiconductor Lasers and Optical Devices
- Cold Atom Physics and Bose-Einstein Condensates
- Chalcogenide Semiconductor Thin Films
- Near-Field Optical Microscopy
- Semiconductor materials and devices
- Graphene research and applications
- Photonic Crystals and Applications
University of Cambridge
2016-2025
University of Science and Technology of China
2012-2015
Saarland University
2014
Cavendish Hospital
2014
ETH Zurich
2005-2008
Boston University
1998-2007
École Polytechnique Fédérale de Lausanne
2007
University of California, Santa Barbara
2005-2006
Ludwig-Maximilians-Universität München
2006
Center for NanoScience
2006
The study of the photophysical properties organic–metallic lead halide perovskites, which demonstrate excellent photovoltaic performance in devices with electron- and hole-accepting layers, helps to understand their charge photogeneration recombination mechanism unravels potential for other optoelectronic applications. We report surprisingly high photoluminescence (PL) quantum efficiencies, up 70%, these solution-processed crystalline films. find that photoexcitation pristine CH3NH3PbI3–xClx...
We demonstrate a deterministic approach to the implementation of solid-state cavity quantum electrodynamics (QED) systems based on precise spatial and spectral overlap between single self-assembled dot photonic crystal membrane nanocavity. By fine-tuning nanocavity modes with high quality factor into resonance any given exciton, we observed clear signatures QED (such as Purcell effect) in all fabricated structures. This removes major hindrances that had limited application enables...
The flourishing field of two-dimensional (2D) nanophotonics has generated much excitement in the quantum technologies community after identification emitters (QEs) layered materials (LMs). LMs offer many advantages as platforms for circuits, such integration within hybrid technologies, valley degree freedom and strong spin-orbit coupling. QEs LMs, however, suffer from uncontrolled occurrences, added to uncertainty over their origin, which been linked defects strain gradients. Here, we report...
We have demonstrated laser cooling of a single electron spin trapped in semiconductor quantum dot. Optical coupling electronic states was achieved using resonant excitation the charged dot (trion) transitions along with heavy-light hole mixing, which leads to weak yet finite rates for spin-flip Raman scattering. With this mechanism, can be cooled from 4.2 0.020 kelvin, as confirmed by strength induced Pauli blockade trion absorption. Within framework information processing, corresponds...
The negatively charged silicon vacancy (SiV) color center in diamond has recently proven its suitability for bright and stable single photon emission. However, electronic structure so far remained elusive. We here explore the by exposing SiV defects to a magnetic field where Zeeman effect lifts degeneracy of sublevels. similar response centers ensemble low strain reference sample proves our ability fabricate almost perfect SiVs, revealing true nature defect's properties. model states using...
An optical source that produces single-photon pulses on demand has potential applications in linear optics quantum computation, provided stringent requirements indistinguishability and collection efficiency of the generated photons are met. We show these conflicting for anharmonic emitters incoherently pumped via reservoirs. As a model coherently single photon source, we propose cavity-assisted spin-flip Raman transitions electron charged dot embedded microcavity. demonstrate using such...
Transition metal dichalcogenides are optically active, layered materials promising for fast optoelectronics and on-chip photonics. We demonstrate electrically driven single-photon emission from localized sites in tungsten diselenide disulphide. To achieve this, we fabricate a light-emitting diode structure comprising single-layer graphene, thin hexagonal boron nitride transition dichalcogenide mono- bi-layers. Photon correlation measurements used to confirm the nature of spectrally sharp...
Monolayer transition metal dichalcogenides have strong Coulomb-mediated many-body interactions. Theoretical studies predicted the existence of numerous multi-particle excitonic states. Two-particle excitons and three-particle trions been identified by their optical signatures. However, more complex states such as biexcitons elusive due to limited spectral quality emission. Here, we report direct evidence two biexciton complexes in monolayer tungsten diselenide: four-particle neutral...
We control the electronic structure of silicon-vacancy (SiV) color-center in diamond by changing its static strain environment with a nano-electro-mechanical system. This allows deterministic and local tuning SiV optical spin transition frequencies over wide range, an essential step towards multi-qubit networks. In process, we infer Hamiltonian revealing large susceptibilities order 1 PHz/strain for orbital states. identify regimes where spin-orbit interaction results suseptibility 100...
The observation of quantum-dot resonance fluorescence enabled a new solid-state approach to generating single photons with bandwidth approaching the natural linewidth transition. Here, we operate in small Rabi frequency limit fluorescence---the Heitler regime---to generate subnatural and high-coherence quantum light from dot. measured single-photon coherence is 30 times longer than lifetime transition, exhibit which inherited excitation laser. In contrast, intensity-correlation measurements...
Spin impurities in diamond have emerged as a promising building block wide range of solid-state-based quantum technologies. The negatively charged silicon-vacancy centre combines the advantages its high-quality photonic properties with ground-state electronic spin, which can be read out optically. However, for this spin to operational bit, full control is essential. Here, we report measurement optically detected magnetic resonance and demonstration coherent single microwave field. Using...
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...
Optically addressable spins in materials are important platforms for quantum technologies, such as repeaters and sensors. Identification of systems two-dimensional (2d) layered offers advantages over their bulk counterparts, reduced dimensionality enables more feasible on-chip integration into devices. Here, we report optically detected magnetic resonance (ODMR) from previously identified carbon-related defects 2d hexagonal boron nitride (hBN). We show that single-defect ODMR contrast can be...
Abstract Solid-state spin–photon interfaces that combine single-photon generation and long-lived spin coherence with scalable device integration—ideally under ambient conditions—hold great promise for the implementation of quantum networks sensors. Despite rapid progress reported across several candidate systems, those possessing coherent single spins at room temperature remain extremely rare. Here we report control conditions a single-photon-emitting defect in layered van der Waals...
Quantum entanglement between distant qubits is an important feature of quantum networks. Distribution over long distances can be enabled through coherently interfacing qubit pairs via photonic channels. Here, we report the realization optically generated electron spin confined in two semiconductor dots. The protocol relies on spin-photon trionic Λ system and erasure Raman-photon path information. measurement a single Raman photon used to project into joint state with interferometrically...