Richard Warburton

Daniel Riedel wins PhD prize!

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.

Nanoscopy on single quantum dots

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

Matthias and Immo’s paper on the n-i-n-i-p structure appears in press

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

NV centres in a tunable microcavity

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

Immo secures Marie-Skłodowska-Curie Fellowship

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

Fabrication paper published

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

Paper published on quantum dot hole spin

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

Paper published on nuclear spin coherence in a quantum dot

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

Paper published on quantum dots in an optomechanical crystal

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

Paper published on quantum fibre pigtail

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 leaves for IBM

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.

Paper published on resonance fluorescence of droplet quantum dots

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

Another new PhD student

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.

New PhD student

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.