Richard Warburton

We report cavity-enhanced Raman scattering on diamond, in particular its use in aligning our tunable microcavities.

We report a spontaneous polarisation in a gated monolayer of MoS2: our paper has just appeared in Nature Nanotechnology!

Daniel Riedel has won the Swiss Nanotechnology PhD Award 2018, an award sponsored by the Hightech Zentrum Aargau. He received the award for his publication in Physical Review X on improving the quality of the photons emitted by NV centres in diamond.

Our paper on imaging single quantum dots has appeared in Nature Photonics. The paper describes how rapid adiabatic passage on a two-level system can be exploited as an on-off switch. This non-linearity enables imaging the quantum dot with a resolution much less than that of a confocal microscope: 30 nm (λ/31) was achieved in this

Our paper Narrow optical linewidths and spin pumping on charge-tunable close-to-surface self-assembled quantum dots in an ultrathin diode has been published in Physical Review B. The paper is part of a successful collaboration with our partners at the Ruhr Universität Bochum and the University of Copenhagen. In this work, InGaAs self-assembled quantum dots are embedded

The flux of coherent photons emitted by single NV centres in diamond is very low on account of three problems: (i) only a small percentage are emitted into the zero-phonon-line (ZPL); (ii) the extraction efficiency out of the high-index diamond host is small; and (iii) the radiative lifetime is large. All three problems can be

With great pleasure we announce that Dr. Immo Söllner, postdoctoral researcher in the Nano-Photonics Group, has been awarded a Marie-Skłodowska-Curie Individual Fellowship for the project “Emitter-mediated Photon-Phonon InteraCtion (EPPIC)”. The project will focus on engineering the interaction of single seminconductor quantum dots with the phononic environment. Immo will work closely with PhDs and postdoctoral researchers

Our paper Fabrication of mirror templates in silica with micron-sized radii of curvature was published in Applied Physics Letters. Routinely, we use a laser ablation process to create mirror templates in silica, usually on flat substrates but also on the end facets of optical fibres. For cavity QED applications, the mode volume should be small. We

Our paper entitled Decoupling a hole spin qubit from the nuclear spins was published in Nature Materials. An electron spin in a quantum dot interacts with the nuclear spins (via the hyperfine interaction) and this limits the spin dephasing times to quite modest values. What about a hole spin? Theory predicts that a heavy-hole spin decouples from the nuclear

Our paper entitled Role of the electron spin in determining the coherence of the nuclear spins in a quantum dot was published in Nature Nanotechnology. The work is a close collaboration between the Poggio and Loss groups in Basel and our partners Arne Ludwig and Andreas Wieck in Bochum. Our motivation was to determine the limits set by the

Immo Söllner’s paper entitled Deterministic Single-Phonon Source Triggered by a Single Photon was published in Physical Review Letters. In the manuscript, a collaboration with Leonardo Midolo and Peter Lodahl from the Niels Bohr Institute, we propose an optomechanical crystal that allows for the simultaneous control of a quantum dot’s photonic and phononic environments. We go on to show how

New web-site created; old one abandoned

Our paper entitled A fiber-coupled quantum-dot on a photonic tip was published in Applied Physics Letters. In the manuscript we present the experimental realization of a quantum fiber-pigtail. The device consists of a semiconductor quantum dot bonded to the end of an optical fibre. The quantum dot is embedded in a photonic “trumpet” to ensure good mode-matching to the

Andreas Kuhlmann starts today at IBM, Rüshlikon in the team of Andreas Fuhrer. Andreas was RJW’s first PhD student in Basel, subsequently a post-doc in the group. We shall miss him but wish him well with his new job, incidentally a QSIT-funded project.

Our paper entitled An artificial Rb atom in a semiconductor with lifetime-limited linewidth was published in Physical Review B. This work, a collaboration with Philipp Treutlein (Basel), Armando Rastelli (Linz), Fei Ding and Oliver Schmidt (Dresden), describes single photon creation using a “droplet” quantum dot. Surprisingly, our first attempts at creating spectrally narrow single photons with this

Matthias Löbl, a graduate of RWTH Aachen University, started his PhD today. Matthias will work on semiconductor quantum dots, specifically the hole spin using resonance fluorescence for spin read-out.

Jonas Roch, an EPFL graduate, started his PhD today. Jonas will work on hybrid structures for nano-photonics, initially on optically-active two-dimensional materials.