LNS: Laboratory for Neutron Scattering and ImagingThe Laboratory for Neutron Scattering and Imaging (LNS) at the Paul Scherrer Institute is responsible for the scientific exploitation, operation and development of neutron scattering and imaging instruments at the Swiss Spallation Neutron Source (SINQ). The team of 50 senior scientists, postdoctoral researchers and PhD students further collaborates on diverse research projects ranging from modern topics in condensed matter physics and materials science to pressing questions in energy research and health care. read more
PhD, Master, Bachelor or Semester projects at the LNSWe offer students the possibility to do their PhD or educational research in our lab. See Teaching and Education for detailed information on Master/Diploma thesis, Bachelor/Semester work and practical courses at the LNS. Currently we have open positions for
- Semester projects on several topics
- Master project - Elastic properties in low dimensional quantum systems
- Master project - Spontaneous magnon decay in non-collinear antiferromagnets
- Master project - Geometrical magnetic frustration beyond insulating ionic compounds
- Master project - Magnetic order in anisotropic triangular materials
- Master project - Magnetic structure of the quantum trimer compound Cs3Cu3Cl8OH
6. June 2017
Field-induced magnetic instability within a superconducting condensateD. Mazzone et al., Science Advances 3, e1602055 (2017). The application of magnetic fields, chemical substitution, or hydrostatic pressure to strongly correlated electron materials can stabilize electronic phases with different organizational principles. We present evidence for a field-induced quantum phase transition, in superconducting Nd0.05Ce0.95CoIn5, that separates two antiferromagnetic phases with identical magnetic symmetry. At zero field, we find a spin-density wave that is suppressed at the critical field μ0H* = 8 T. For H > H*, a spin-density phase emerges and shares many properties with the Q phase in CeCoIn5. These results suggest that the magnetic instability is not magnetically driven, and we propose that it is driven by a modification of superconducting condensate at H*.
28. April 2017
Bound States and Field-Polarized Haldane Modes in a Quantum Spin LadderS. Ward, M. Mena et al., Physical Review Letters 118, 177202 (2017). The challenge of one-dimensional systems is to understand their physics beyond the level of known elementary excitations. By high-resolution neutron spectroscopy in a quantum spin-ladder material, we probe the leading multiparticle excitation by characterizing the two-magnon bound state at zero field. By applying high magnetic fields, we create and select the singlet (longitudinal) and triplet (transverse) excitations of the fully spin-polarized ladder, which have not been observed previously and are close analogs of the modes anticipated in a polarized Haldane chain. Theoretical modeling of the dynamical response demonstrates our complete quantitative understanding of these states.
18. April 2017
20 years of SINQIn 1997 the Swiss spallation neutron source SINQ started its user operation. PSI has celebrated the 20th anniversary of SINQ with a scientific symposium on April 18, 2017 together with many colleagues from Switzerland and abroad. At the symposium it was not only looked back at past achievements, also recent scientific highlights were presented as well as the SINQ neutron guide and instrument upgrade program that will make SINQ fit for the next 20 years. Finally, the symposium also marked the change of the NUM Division Head from Kurt N. Clausen to Christian Rüegg.
27. March 2017
Tuning the multiferroic mechanisms of TbMnO3 by epitaxial strainK. Shimamoto, S. Mukherjee et al., Scientific Reports 7, 44753 (2017). A current challenge in the field of magnetoelectric multiferroics is to identify systems that allow a controlled tuning of states displaying distinct magnetoelectric responses. Here we show that the multiferroic ground state of the archetypal multiferroic TbMnO3 is dramatically modified by epitaxial strain. Neutron diffraction reveals that in highly strained films the magnetic order changes from the bulk-like incommensurate bc-cycloidal structure to commensurate magnetic order. Concomitant with the modification of the magnetic ground state, optical second-harmonic generation (SHG) and electric measurements show an enormous increase of the ferroelectric polarization, and a change in its direction from along the c- to the a-axis. Our results suggest that the drastic change of multiferroic properties results from a switch of the spin-current magnetoelectric coupling in bulk TbMnO3 to symmetric magnetostriction in epitaxially-strained TbMnO3. These findings experimentally demonstrate that epitaxial strain can be used to control single-phase spin-driven multiferroic states.
17. March 2017