Prof. Dr. Christian Rüegg

Head - NUM Division Christian Rüegg
Paul Scherrer Institute PSI
Forschungsstrasse 111
5232 Villigen PSI
Since 2022 Member of the ETH Board and representative of the four Research Institutes (PSI, Empa, WSL, Eawag)  
Since 2020 Director, Paul Scherrer Institute  
Since 2020 Professor, Department of Physics, ETH Zurich  
Since 2020 Professor, Institute of Physics, EPF Lausanne  
Since 2012 Professor, Department of Quantum Matter Physics, University of Geneva
2011-2021 Honorary Professor, London Centre for Nanotechnology (LCN), University College London (UCL)
2017-2020 Head of Division, Research with Neutrons and Muons, Paul Scherrer Institute  
2011-2016 Head of Laboratory, Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute
2009-2011 Reader in Physics (associate professor, tenured), LCN and Dept. of Physics and Astronomy , UCL
2008-2011 Royal Society University Research Fellow, LCN and Dept. of Physics and Astronomy, UCL
2008-2009 Lecturer in Physics (assistant Professor, tenured), LCN and Dept. of Physics and Astronomy, UCL
2005-2008 Postdoctoral Research Associate, LCN and Dept. of Physics and Astronomy, UCL
2001-2005 Ph.D. studies, Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institute
1996-2001 Undergraduate studies (physics) at ETH Zurich

My research projects focus on systematic studies of strongly correlated quantum phenomena in low-dimensional spin systems, single-molecule and frustrated magnets, and novel emergent materials. In addition to my primary research tools of neutron spectroscopy and diffraction, my expertise extends to complementary techniques including X-ray scattering, specific heat, magnetic susceptibility, magnetocalorimetry and thermal transport measurements. All of my studies involve extreme conditions, as high magnetic fields and pressures in combination with ultra-low temperatures are required to investigate e.g. spin correlations in quantum materials. The results from a number of my projects are of interest to people working particularly in the fields of phase transitions, quantum condensates and other forms of collective quantum behaviour, as well as in several related areas where mesoscopic quantum states are under active exploration for future technological applications.


  • Quantum phase transitions in strongly correlated systems
  • Spin dynamics in low-dimensional and frustrated quantum magnets
  • Bose condensation in magnetic materials and hardcore-boson models
  • Novel metal-organic quantum spin systems
  • Interplay of frustration with heavy-electron physics
  • Spin and lattice dynamics in novel iron-based superconductors
  • Development of new neutron scattering methods and instrumentation

Experimental Techniques:

  • Neutron inelastic and elastic scattering
  • Inelastic and elastic X-ray scattering (synchrotron- and laboratory-based)
  • Bulk measurements (specific heat, magnetization, magnetic susceptibility, and basic NMR)
  • Extreme conditions (low-temperatures, high magnetic fields, and high pressure)


Quantum criticality in the quantum spin-dimer material TlCuCl3, Nature Physics 10, 373 (2014).
2015ERC Consolidator Grant
2011Erwin Felix Lewy-Bertaut Prize
2010Nicholas Kurti European Science Prize
2006Swiss Physical Society Award 2006 for General Physics
2005Medal of the ETH Zurich for Ph.D. thesis
2002Young Scientist Award, 1st PSI Summer School on Condensed Matter Research, Zuoz
2001Young Scientist Award, Int. Conf. on Neutron Scattering, Munich
2001Diploma with distinction, ETH Zurich
2014 Mott Physics Beyond Heisenberg, MPBH 2014, Oxford, UK
2013 Mott Physics Beyond Heisenberg, MPBH 2013, Monte Verita, Switzerland
2012 Mott Physics Beyond Heisenberg, MPBH 2012, EPF Lausanne, Switzerland
2012 Experiments in Quantum Matter, UK-CH Workshop, Zermatt, Switzerland
Since 2009Program committees and international advisory boards for conferences: QENS and WINS (San Sebastian, 2022), LT29 (Sapporo, 2022), ICANS (Chattanooga, 2019), ECNS (St. Petersburg, 2019), UBEC (Pittsburgh, 2019), LT28 (Gothenburg, 2017), SPG Annual Meetings (Lugano, Vienna, Fribourg and Linz, 2013-2016), SWM (Les Diablerets, 2011, 2013 and 2016), μSR 2014 (Grindelwald, 2014), MaNEP Winter School (Saas-Fee, 2013), ICNS (Edinburgh, 2013). Joint Users’ Meeting JUM@P (PSI, 2009, 2011 and 2013), QCNP (Karlsruhe and Dresden, 2009 and 2012), Topological Materials (Grenoble, 2012).
Since 2008Scientific advisory boards: Neutron Advisory Committee, J-PARC, Japan (2018-), Chairman, Scientific Advisory Board SwedNess, Swedish Foundation for Strategic Research (2016-2021), Scientific Advisory Board, Lund Institute for Advanced Neutron and X-ray Science LINXS, Sweden (2016-2021), Chairman, Scientific Council, Institut Laue Langevin, Grenoble (2017-2019), Scientific Advisory Board, Maier-Leibnitz Zentrum, Germany (2016-2019), UK-ESS Instrument Project Board (2016-2019), Scientific and Technical Advisory Committee, High-field Magnet Project, Helmholtz-Zentrum Berlin (2013-2019), Access Panel, Rutherford Appleton Laboratory (2015-2018), Instrument Collaboration Board, European Spallation Source ERIC (2015-2018), Delegate for SINQ, European Neutron Scattering Association ENSA (2012-2018), Annual Review, European Spallation Source ERIC (2017), Scientific Council, Institut Laue Langevin (2013-2016), Scientific Council, Laboratoire National des Champs Magnetiques Intenses (2012-2016), External Assessment Committee, Leon Brillouin Laboratory (2014), Instrumentation Subcommittee, Institut Laue Langevin (2012-2013), College 4, Institut Laue Langevin (2009-2012), Instrument Review Panel, Institut Laue Langevin (2011), Joint Users’ Association of PSI JUSAP (2008-2011).
Since 2017Policy, industry and innovation: Innovaare AG, Member of the Board (2020-), Switzerland Innovation, Stiftungsrat (2020-), TECHNOPARK Aargau, Stiftungsrat (2020-), European Spallation Source ERIC, Lund, Swiss delegate to ESS Council (2018-), Swiss In-Kind Advisory Committee for ESS, State Secretariat for Education, Research and Innovation (SERI), Co-Chairman (2017-), Swiss Industry Liaison Office for International Research Organisations, State Secretariat for Education, Research and Innovation (SERI), Steering Committee (2017-), Swiss Competence Center for Energy Research – Efficient Technologies and Systems for Mobility, Board member and delegate for PSI (2018-2020), Swiss Accelerator Research and Technology Initiative CHART, Collaboration Council (2018-2019).
Since 2013Association MaNEP Switzerland, Member of the executive board (president, 2017-2021)
Since 2023Schweizerische Akademie der Technischen Wissenschaften SATW
Since 2014International Society for Neutron Radiology ISNR
Since 2008Swiss Physical Society SPG/SPS, CH (2012-2016 Member of the board, condensed matter physics)
Since 2002Swiss Neutron Scattering Society SGN/SNSS, CH
2009 - 2020Institute of Physics, UK