Joint Swiss-Russian Workshop on Quantum Magnetism and Polarized Neutrons

1-4 March 2006

Paul Scherrer Institut, Switzerland

You can download a zip-file with the presentations here zip

Scope

Neutron scattering with polarized neutrons has been used in fundamental and condensed matter physics for many years, in spite of the low flux of polarized beams. Nowadays, polarized neutron scattering is a fast developing experimental method that finds applications in various fields of condensed-matter research. Examples are

• determination of magnetic structures and spin densities;
• identification of magnetic fluctuations and their different modes;
• comprehensive investigation of spin-phonon coupling;
• separation of coherent from incoherent processes;
• investigation of spin chirality.

Goal

At the Swiss Spallation Neutron Source SINQ at the Paul Scherrer Institut, we have installed polarised neutron devices that allow us to investigate these topics. Because polarised neutron scattering is a rather complex technique, the first goal of this workshop will be to inform our Russian partners about the current capabilities of polarised neutrons at SINQ in order to promote scientific collaboration in the future. The second goal is to define in detail promising areas in the field of quantum magnetism where both parties have joint scientific interest both from the experimental and theoretical point of view.

Location

The Workshop will take place in the lecture hall of PSI (auditorium WGHA).

Speakers

Altough the workshop was primarly organised between Russian and Swiss scientists interested by the application of neutron polarisation analysis, speakers from other leading institutions in the field (CEA, Grenoble; CNRS Grenoble; ILL, Grenoble; LLB, Saclay; T.U. Munich; Oxford Univ.; Univ. College Dublin; Univ. California) have accepted to make presentations. Please see the programme below.

Programme

Wednesday, March 1.

8-30 Welcome (K. Clausen)
8-40 Description of the instrumentation at SINQ (J. Mesot) pdf
9-10 Polarized Neutrons for Condensed Matter Investigations at PNPI (A.I. Okorokov) pdf
9-40 Growth and characterization of complex oxide single crystals (K. Conder, E. Pomjakushina) pdf

10-40 Chiral fluctuations in non-centrosymmetric cubic crystals and polarised neutron cross-sections (S. Maleyev) pdf
11-10 Magnetic correlations in incommensurate MnSi and Cr: Investigations with polarised neutrons (P. Boni) pdf

13-30 Critical behaviour of MnSi under applied field (S. Grigoriev) pdf
14-00 Effect of the Dzyaloshinskii-Moriya interaction on the muon spin-lattice relaxation rate in MnSi (A. Yaouanc) pdf
14-30 Theory of the helical spin crystal. A candidate for the partially ordered state of MnSi (B. Binz) pdf

15-30 Emergent Soliton Chirality and Spin Currents in a Quantum Antiferromagnet (H.B. Braun) pdf
16-00 Inelastic neutron studies of the trivial dynamical magnetochirality in the quantum spin chains (E. Lorenzo) pdf
16-30 Poster session

1. Spin-wave dynamics of the Invar Iron-Nickel alloys studied by polarized SANS (S.V. Metelev) pdf
   
2. Incommensurate magnetic structure in Y(1-x)TbxMn6Sn6 (Yu.O.Chetverikov) pdf
   
3. Spin dynamics in the organic quantum magnet (C5H12N)2CuBr4 (B. Thielemann) pdf
   
4. Itinerant versus localized spins in NaxCoO2 (J.L. Gavilano) pdf

Thursday, March 2.

8-30 Magnetic order in the pseudogap phase of high-Tc superconductors (Ph. Bourges) pdf
9-00 Magnetism of two-dimensional systems (G. Petrakovskii) pdf
9-30 Spin excitation spectrum the S=1/2 square lattice Heisenberg antiferromagnet elucidated with polarization analysis (N. Christensen) pdf

10-30 Field-induced quantum phase transitions in 2D antiferromagnets R2CuO4 (S. Gavrilov) pdf
11-00 Competing spin interactions as a new route to multiferroic materials (M. Kenzelmann) pdf
11-30 Universal Scaling Relations in Strongly Anisotropic Magnets (A. Praz) pdf

13-30 Frustrated defects in antiferromagnets (A. Syromyatnikov) pdf
14-00 Spin–reorientation transitions in the intermetallic compounds (A.N. Pirogov) pdf
14-30 Representation analysis of magnetic structures: « time inversion or « reality of the magnetic moments» ? (J. Schweizer) pdf

15-30 Magnetic order in Er3+ halides (K. Kraemer) pdf
16-00 Magnetic and quadrupolar ordering in Kondo crystal CeB6 (V. Plakhty) pdf
16-30 Round table to define projects that can be realised before the second part of the seminar be organised in Petersburg

Friday, March 3.

8-30 Antiphase magnetic proximity effect in YBa2Cu3O7 / La2/3Ca1/3MnO3 multilayers (Ch. Niedermayer) pdf
9-00 Magnetic depth profiling of FM/AF/FM trilayer using polarised neutron reflectometry with polarisation anaysis (Ch. Schanzer) pdf
9-30 Small Angle Polarized Neutron Scattering from carriers in heavy fermion compounds (G.Kopitsa/ S. Grigoriev) pdf

10-30 Can Neutron Scattering measure Quantum Entanglement in Quantum Magnets and in Hydrogen? (R.A. Cowley) pdf
11-00 Polarised Neutrons and Polarised Nuclei (P. Hautle/F. Piegsa) pdf

13-30 Neutron polarimetry at SINQ: first results (M. Janoschek) pdf
14-00 Determination of Complex magnetic structures with neutron polarimetry (P.J. Brown) pdf
14-30 Inelastic Spherical Neutron Polarimetry on low-dimensional quantum-spin oxides (L.P. Regnault) pdf

15-30 Ground states in Cu2Te2O5X2 and Cu3ZO6 systems with coupled spin clusters (O. Zaharko) pdf
16-00 Spin spiral ground state and low energy excitations in antiferromagnets with Dzyaloshinsky-Moriya interactions: Cu2Te2O5X2 (M. Elhajal/F. Mila) pdf
16-30 Conclusion (V. Plakhty)
17-00 Visit of PSI facilities SINQ, Muon Facility
18-00 Round Table about polarised neutron scattering

Saturday, March 4.

Check-out and departure

Registration

Organisers

Sponsors

Accomodation

Abstracts

Presentations

Contacts