1. Department of Information Technology and Electrical Engineering, ETH Zurich, CH-8092 Zurich, Switzerland
2. Department of Applied Physics, KTH Royal Institute of Technology, SE-16440 Stockholm, Sweden
3. Department of Physics, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
4. Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
5. Laboratory for Multiscale Materials Experiments, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
6. Rutherford Appleton Laboratory, ISIS Neutron and Muon Facility, Didcot, OX11 0QX Oxfordshire, U.K.