Description
chairman: C. Niedermayer, M. Kenzelmann, H.Luetkens, C. Rüegg
Dr
N B Christensen
(Materials Research Division, Risø-DTU, National Laboratory for Sustainable Energy, Technical University of Denmark, Denmark)
16/09/2011, 09:30
Multiple Order Parameter Systems
Talk
In this contribution, the spin and charge “stripe” ordering tendencies observed by neutron and x-ray diffraction in La-based cuprate superconductors [1,2] will be discussed with emphasis on magnetic field effects on these correlations [3,4]. In particular, we will relate our new diffraction results [4] with evidence for hole-pockets arising from ARPES experiments conducted at the SIS beamline...
Dr
Samuele Sanna
(Dipartimento di Fisica "A.Volta" e Unita CNISM di Pavia, 27100 Pavia, Italy)
16/09/2011, 09:55
Multiple Order Parameter Systems
Talk
Here we present an extensive μSR study of the microscopic behaviour of the two prototypes of the cuprate and pnictide families, namely YBa2Cu3O6+x and REFeAsO1-xFx (RE=La, Sm, Ce ). We compare the effect of carrier doping, magnetic dilution, disorder and pressure on the electronic properties of both compounds mainly at the magnetic (M) to superconducting (SC) crossover.
The studies on...
Mr
M Bendele
(Physik-Institut der Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich and Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI)
16/09/2011, 10:20
Multiple Order Parameter Systems
Talk
We report on a detailed study of the electronic phase diagram of FeSe1−x under pressure by means of muon-spin rotation and AC magnetization. Whereas at low pressures the system is solely superconducting at low-temperatures, one observes the occurrence of a static magnetic order at a pressure of ≃ 0.8GPa. For this pressure, bulk superconductivity coexists and competes on short length scales...
Prof.
Elvezio Morenzoni
(Paul Scherrer Institut)
16/09/2011, 10:40
Multiple Order Parameter Systems
Talk
The Meissner effect and the associated perfect bulk diamagnetism are, besides zero resistance and gap opening, characteristic features of the superconducting state. In the pseudogap phase of cuprates unusual diamagnetic signals as well as anomalous proximity effects have been detected but a Meissner effect has never been observed. Here, we have probed by low energy muSR the local diamagnetic...
Mr
J S White
(Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen, Switzerland)
16/09/2011, 11:20
Multiple Order Parameter Systems
Talk
The family of magnetically-induced multiferroic materials that exhibit coupled magnetic and electric order offer great promise for future applications. A detailed understanding of the coupling mechanism between magnetism and ferroelectricity facilitates the development of new materials that may allow controllable multiferroic properties to emerge at room temperature. Here, we will focus on our...
Dr
A Poole
(Laboratory for Neutron Scattering, Paul Scherrer Institut, 5232 Villigen-PSI, Switzerland)
16/09/2011, 11:45
Multiple Order Parameter Systems
Talk
This presentation will give a summary of the polarized neutron experiments that have been performed at the Paul Scherrer Institut using the MuPAD spherical neutron polarimetry (SNP) set-up on TASP, [1]. It will include a discussion of the approach taken to analysis and interpretation of polarimetry data recently gathered on the high temperature multi- ferroic CuO, [2].
SNP experiments...
Dr
Nicholas C. Plumb
(Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland)
16/09/2011, 14:30
Multiple Order Parameter Systems
Talk
A unique system at the SIS beamline combines two powerful condensed matter experimental tools: a pulsed laser deposition (PLD) growth chamber and high-resolution angle-resolved photoemission spectroscopy (ARPES), connected by in situ UHV transfer. The PLD-ARPES system allows us to study the momentum-resolved electronic structure of novel materials that have not previously been accessible to...
Dr
Mihaela FALUB
(Paul Scherrer Institut, Swiss Light Source)
16/09/2011, 14:55
Multiple Order Parameter Systems
Talk
Hole-doped manganese perovskites La1-xSrxMnO3 (LSMO) have stimulated a renewed scientific and technological interest because of their complex electronic and magnetic properties. Angle-resolved photoemission (ARPES), which directly probes the k-dependent electronic structure, could not be used to study LSMO single crystals because of their isotropic cubic symmetry (no preferential cleaving...
Dr
Vladimir Strocov
(Swiss Light Source, Paul Scherrer Insitute)
16/09/2011, 15:20
Multiple Order Parameter Systems
Talk
ARPES experiments in the soft-X-ray energy range bring advantages of free-electron final states, simplified matrix elements and increasing photoelectron escape depth. The latter, along with enhancement of the bulk sensitivity, improves intrinsic resolution in surface-perpendicular momentum. This enables investigations of electronic structure under reliable control of the three-dimensional (3D)...
Dr
S R Dunsiger
(Physik Department, Technische Universität München, Garching, Germany)
16/09/2011, 16:05
Multiple Order Parameter Systems
Talk
Technologically, a semiconductor which is also a ferromagnet has exciting potential for spintronic applications, where logic and memory operations could in principle be integrated on a single device. Artificial heterostructures based on such ferromagnets show immense promise, in particular for the injection of polarised spins into a semiconducting substrate. From a fundamental perspective,...
Dr
Souliman El Moussaoui
(Paul Scherrer Institut)
16/09/2011, 16:30
Multiple Order Parameter Systems
Talk
Nanostructures of GdFeCo have been fabricated using lithography and lift-off techniques. Their magnetic properties were revealed using the Photoemission Electron Microscope (PEEM) available at the SIM beamline. Employing fs-optical excitation, we have been able to manipulate the magnetization of the nanostructures on very short time scales. By performing these experiments we have found...
Mr
P Merchant
(University College London UCL, UK)
16/09/2011, 16:50
Multiple Order Parameter Systems
Talk
Quantum spin ladders provide an exciting opportunity to study aspects of quantum critical phenomena and low-dimensional physics, serving as a bridge between 1 and 2 dimensional quantum systems [1]. BiCu2PO6 (BCPO) is a new spin 1 two-leg ladder system, with an energy scale of 2 exchange interactions in the range between the values found in cuprate ladders (~100meV) and the metal-organic...
