1. Condensed Matter Physics Big Facility Physics26th Jan 2004 Sub Heading “Big Facility” Physics in Grenoble ESRF: X-rays ILL: neutrons

2. Condensed Matter Physics Big Facility Physics26th Jan 2004 “Big Facility” Physics near Zurich - Paul Scherrer Institut S  S: muons SINQ: neutrons SLS: X-rays

3. Condensed Matter Physics Big Facility Physics26th Jan 2004 Low energy muons for investigation of: Magnetic fields in thin films and surfaces

4. Condensed Matter Physics Big Facility Physics26th Jan 2004 The apparatus for producing a beam of low energy muons

5. Condensed Matter Physics Big Facility Physics26th Jan 2004 muons are implanted in the sample surface <= HERE at a tuneable energy of 1 - 30 keV the muons come in <= HERE with 4 MeV energy and are spin- polarised Original apparatus designed and constructed by E. Morenzoni at Paul Scherrer Institut

6. Condensed Matter Physics Big Facility Physics26th Jan 2004 WHY USE (+ve) MUONS ? its spin precesses in the local B-field the e + tends to be emitted along the muon spin direction the spin-polarised muon arrives in the sample it decays, giving an e + in about 2  s

7. Condensed Matter Physics Big Facility Physics26th Jan 2004 After implanting a large number of muons... => The muon spin sweeps around like a lighthouse - the probability of an e+ arriving at a fixed detector => oscillates (and decays) with time (after implantation)

8. Condensed Matter Physics Big Facility Physics26th Jan 2004... which has been implanted at a known depth - - controlled by its energy... The frequency of precession measures the magnetic field AT the muon...

9. Condensed Matter Physics Big Facility Physics26th Jan 2004 First ever measurement of field profile on a nm scale just inside a superconductor Field Distance below surface of YBCO T.J. Jackson et al. Phys. Rev. Lett. 84, 4958-4961 (2000) increasing temperature

10. Condensed Matter Physics Big Facility Physics26th Jan 2004 Current Developments new samples: low Tc super- conducting films ferromagnetic- normal and ferro- superconducting multilayers CMR+HighTc films micro-structured superconductors - and a new x 10 intensity muon beamline being developed at PSI a new muon moderation cryostat - developed in Birmingham

11. Condensed Matter Physics Big Facility Physics26th Jan 2004 Magnetic Flux Lines in superconductors Each flux line Carries a flux of  0 = h/2e Flux lines Current Type-II superconductor Motion

12. Condensed Matter Physics Big Facility Physics26th Jan 2004 F T H FcFc Liquid Moving Bragg glass Smectic Plastic Vortex Glass Bragg glass D=3 Vortex Matter H -T Phase DiagramVortex Matter Dynamical Phase Diagram H T normal state vortex solid vortex liquid H c2 TcTc Meissner state

13. Condensed Matter Physics Big Facility Physics26th Jan 2004 Detected by small-angle neutron diffraction SANS

14. Condensed Matter Physics Big Facility Physics26th Jan 2004 Diffraction pattern from a  Flux Lattice in niobium EPSRC – funded 11 T cryomagnet

15. Condensed Matter Physics Big Facility Physics26th Jan 2004 Results from YBCO => Phys Rev Lett, Feb 2004 B = 1 T pattern Four stretched triangular lattices at low fields

16. Condensed Matter Physics Big Facility Physics26th Jan 2004 Results from YBCO => Phys Rev Lett, Feb 2004 B = 11 T pattern Square lattice of flux lines at high fields Due to fourfold symmetry of d-wave flux line cores

17. Condensed Matter Physics Big Facility Physics26th Jan 2004 Calculations of flux lattice structure and energy s-wave: but forced to be square d-wave: orientation rotated 45 deg d-wave observed orientation lowest energy

18. Condensed Matter Physics Big Facility Physics26th Jan 2004 Future Work – mainly on “Vortex Matter” flux lattice structures and pairing mechanisms in unconventional superconductors flux lattice melting in low-T c superconductors X-ray observation of flux line cores flux line motion and motion-induced ordering flux-line-like molecular structures Other neutron scattering, including inelastic neutron scattering studies of fluctuations near QCP in Sr 3 Ru 2 O 7

19. Condensed Matter Physics Big Facility Physics26th Jan 2004 Future Developments in neutron scattering Spallation Neutron Source, Oak Ridge USA

20. Condensed Matter Physics Big Facility Physics26th Jan 2004 European Spallation Source? Probably in the UK ILL will be competitive for the next 10 years

21. Condensed Matter Physics Big Facility Physics26th Jan 2004