Joint Swiss-Russian Workshop on Quantum Magnetism and Polarized Neutrons

1-4 March 2006

Paul Scherrer Institut, Switzerland

Scope

Neutron scattering with polarized neutrons has been used in fundamental and condensed matter physics since many years despite 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 scientific topics. Because polarised neutron scattering is a rather complex technique, the goal of this seminar will be first to inform our Russian partners about the current capabilities of polarised neutrons at SINQ in order to promote scientific collaboration in 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.

Speakers

Altough the workshop was primarly organised between Russian and Swiss scientists interested by the applicaiton of neutron polarisation analysis, speakers from other leading institutions in the field (CEA, Grenoble; CNRS Grenoble; ILL, Grenoble; LLB, Saclay; T.U. Munich; Oxford Uni., Dublin Univ.) 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)
9-10 Polarized Neutrons for Condensed Matter Investigations at PNPI (A.I. Okorokov)
9-40 Growth and characterization of complex oxide single crystals (K. Conder, E. Pomjakushina)

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

13-30 Critical behaviour of MnSi under applied field (S. Grigoriev)
14-00 Effect of the Dzyaloshinskii-Moriya interaction on the muon spin-lattice relaxation rate in MnSi (A. Yaouanc)

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

Thursday, March 2.

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

10-30 Field-induced quantum phase transitions in 2D antiferromagnets ReCuO4 (V.P. Plakhty)
11-00 Competing spin interactions as a new route to multiferroic materials (M. Kenzelmann)
11-30 Universal Scaling Relations in Strongly Anisotropic Magnets (A. Praz)

13-30 Frustrated defects in antiferromagnets (A. Syromyatnikov)
14-00 Spin–reorientation transitions in the intermetallic compounds (A.N. Pirogov)

15-00 Representation analysis of magnetic structures: « time inversion or « reality of the magnetic moments» ? (J. Schweizer)
15-30 Magnetic order in Er3+ halides (K. Kraemer)
16-00 Magnetic and quadrupolar ordering in Kondo crystal CsB6 (V. Plakhty)
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 YB\a2Cu3O7 / La2/3Ca1/3MnO3 multilayers (Ch. Niedermayer)
9-00 Magnetic depth profiling of FM/AF/FM trilayer using polarised neutron reflectometry with polarisation anaysis (Ch. Schanzer)
9-30 Small Angle Polarized Neutron Scattering from carriers in heavy fermion compounds (G.Kopitsa/ S. Grigoriev)

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

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

15-30 Ground states in Cu2Te2O5X2 and Cu3ZO6 systems with coupled spin clusters (O. Zaharko)
16-00 Spin spiral ground state and low energy excitations in antiferromagnets with Dzyaloshinsky-Moriya interactions: Cu2Te2O5X2 (M. Elhajal/F. Mila)
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

Organisers

S.V. Maleyev, S.V. Grigoriev, B. Roessli

Sponsors

Paul Scherrer Institut
Russian Foundation for Basic Research
Swiss National Science Foundation

Accomodation

Abstracts

For speakers who have not sent an abstract yet, please do it as soon as possible

Presentations

Contacts

Denise.Castellazzi@psi.ch
Bertrand.Roessli@psi.ch