Quantum Information and Nanoscale Metrology Group

For all projects listed above, you, as the PhD candidate, should be enthusiastic and driven. In return, you will be part of an active group of driven students and postdoctoral fellows working together in an exciting field of physics.

Currently, we have multiple PhD studentships available with flexible starting dates as early as December 2011 on Solid-State Spin Qubits as well as on Nanoplasmonics. Contact us if you are interested in joining us!

Interfacing Spin and Photon Qubits from Quantum Dots

Confined and isolated spins carry great promise for quantum information science as quantum bits. Optically active semiconductor quantum dots provide not only the confinement, but also clean optical access to the individual spin states under study. This comes at the expense of many-body effects in the presence of weak coupling to nearby charge, spin, and phonon reservoirs. In this project, we study the dynamics of few spins in quantum confined systems such as coupled quantum dots. Some of our aims include all-optical control of single spins and their selective interaction with mesoscopic ensembles, demonstration of spin-photon entanglement, and quantum memory in spin ensembles. As a PhD candidate, you should have a strong interest in experimental quantum optics, optical spectroscopy, confined spin systems and quantum information science.

Novel Quantum Emitters in Diamond for Quantum Metrology and Quantum Computing:

An ultra-pure diamond crystal has no colour. The famous colours of diamond are due to what are known as color centers. They are formed by one or few atoms buried inside the carbon-based crystal and the energy separations of the electronic orbital levels of these centres determine the colour of optical absorption and emission. Recently, these atom-like discrete optical transitions has provided a suitable test bed for applications of quantum information processing, from single photon emission for quantum cryptography to observation of quantum gates and quantum memory via selected spin interactions of electrons and nuclei. While there are hundreds of known color centres in diamond, only one (Nitrogen-Vacancy diatomic defect) has been studied extensively. In our research group we focus on alternative color centres, both naturally occurring and artificially implanted, to investigate their feasibility or even superiority for similar quantum information science applications. Currently studied colour centres include Nickel, Silicon, and Chromium as impurity atoms. As a PhD candidate, you should have a strong interest in experimental quantum optics, optical spectroscopy, confined spin systems and quantum information science. In return, you will be part of an active group of driven students and postdoctoral fellows working together in an exciting field of physics.

Plasmonic Cavity Quantum Electrodynamics and Nano-Optics

Plasmon polaritons are collective coherent oscillations of the free electrons of a metal at the optical frequencies. In this project we study the coupling of these collective modes to optical fields with the main aim of realizing an analogue of solid-state-based cavity quantum electrodynamics via light confinement well beyond the diffraction limit. Using the plasmon polariton modes of metallo-dielectric nanostructures, we study the coupling of individual and ensemble quantum systems (single photon sources) to the localized fields in the vicinity of the nanostructures. Further, we study how sub-wavelength structures of a medium such as a two-dimensional array of metallic nanowires, alter the material-based properties yielding novel and exotic responses such as negative refractive indices. As a PhD candidate, you should have a strong interest in experimental quantum optics, optical spectroscopy, nanoplasmonics and nanofabrication and numerical simulations using the FDTD technique.

Ongoing Collaborations

Uni. of Cambridge - Atomic, Mesoscopic and Optical Physics Group
ETH-Zurich Quantum Photonics Group
BU Psec Spectroscopy and Near-Field Microscopy Laboratory
Imperial College London - Stefan Maier
JQI, Maryland - Jacob Taylor
University of Stuttgart - Fedor Jelezko
USTC, Hefei - Jian-Wei Pan
Uni. of Melbourne - Steven Prawer
University of Saarland - Christoph Becher