Neutron scattering study of the field-induced soliton lattice in CuGeO3

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Motivated by synthesis of new antiferromagnetic compounds with weak exchange coupling, a study of high magnetic field properties of the Heisenberg model on a square-lattice is undertaken here. Ordered spins at zero temperature cant toward the field direction inducing coupling of transverse and longitudinal magnon modes. Resulting interactions renormalize the ground-state energy and the dispersion relation below a threshold field H∗ = 0.76Hsat, where one-magnon excitations starts to become unstable and acqui

Conventional Hall devices are widely employed to measure magnetic fields produced by millimetre sized (or larger) current-caring conductors or permanent magnets with a standard active area of about (100 um)^2. Micro-Hall sensors have recently emerged as a powerful and sensitive tool for the investigation of local magnetic field properties of the micro and nano-structures. The conventional Hall effect devices are based on non-magnetic materials (typically semiconductors e.g: AlGaAs/GaAs and InSb or semimetal

In this paper the effects of the magnetic self-field on the transport properties of a multi-layer high-Tc superconducting (HTS) cable are investigated by means of 2D finite element method (FEM) simulations. Analyzed is a 3-layer HTS cable, but the developed methods can be used for a different number of layers. The superconductor is described by the non-linear power-law relation E=Ec(J/Jc)^n, where the parameters Jc and n depend on the magnetic field experienced by the material. This dependence decreases the

We study the effect of a magnetic field (applied along the c axis) on the low-energy, incommensurate magnetic fluctuations in superconducting La1.82Sr0.18CuO4. The incommensurate peaks at 9 meV, which in zero field were previously shown to sharpen in q on cooling below T-c [T. E. Mason , Phys. Rev. Lett. 77, 1604 (1996)], are found to broaden in q when a field of 10 T is applied. The applied field also causes scattered intensity to shift into the spin gap. We point out that the response at 9 meV, though occ

We study the dynamic motion of magnetic structures composed of micron-size ferromagnetic particles. The supraparticle structures are retained in a microfluidic channel by a local oscillating magnetic field while subjected to a viscous liquid flow. We analyze the position of the magnetic structures as a function of the flow velocity and of the frequency and amplitude of the magnetic field. We also study the conditions for release of the magnetic structures from the localized magnetic field region.

We propose a new approach for magnetic microbead transport in microfluidic channels over long-range distances by the actuation of a simple array of planar coils. The latter are placed in a uniform static magnetic field, generated by permanent magnets. This static field imposes a magnetic moment with a fixed sense to the microbeads. As a consequence, the magnetic energy and the magnetic forces acting on the beads are strongly enhanced, when the beads are placed in a spatially varying field. Only the very sma

Using the SULTAN test facility the d.c. behaviour of three subsize NbTi cable-in-conduit (CIC) conductors has been studied. The d.c. performance of the cables is compared with the critical currents and the current sharing temperatures expected from the strand data. As a basis for this comparison the critical current of the NbTi strands has been measured in the temperature range of 4.2-6.5 K in magnetic fields of up to 7.5 T. The d.c. performance of the NbTi subsize conductors has been found to be not signif

We introduce a variational total-energy functional to treat finite homogeneous electric fields with periodic boundary conditions and show that this functional can be implemented within a Car-Parrinello molecular dynamics scheme. The Coupling to an electric field is achieved through the Berry-phase expression of the polarization. The minimization of this extended functional gives a ground state which describes the polarized state in ail electric field. For a crystalline system, the ground state of this exten

Planar magnetic sensor, made in particular via CMOS techniques on a semiconductor substrate (1) of for example parallelepiped shape. It includes an amorphous ferromagnetic core (10) in the shape of a Greek cross which occupies the two diagonals of the square defined by the outer contour (90) of the excitation coil (9), the latter being made in the form of a planar winding of square shape. One thus measures, via flat detection coils (70, 80 and 71, 81) which are mounted in series and in a differential arrang

In certain power applications, Bi-2223 conductors carrying AC current will be subjected to external magnetic fields, whose orientation and conductor’s geometry are of major significance for the AC loss magnitude. This paper investigates the influence of the geometry and aspect ratio of non-twisted Bi-2223 conductors in reducing the AC loss for such applications. A numerical model of high-Tc materials has been used in FEM simulations. The model incorporates power-law E-J characteristics with Jc defined by bo

Experimental data characterizing indoor electric and magnetic fields radiated by power line communication (PLC) systems and used for the calculation of a local transfer function (coupling factor) are presented. It is shown that the indirect determination of electric field using magnetic field measurements and assuming a plane wave approximation may result in an underestimation of the electric field. Additionally, it is shown that the radiated field magnitudes vary significantly as a function of the position

We have investigated the orbital magnetization of tunable two-dimensional electron-systems (2DES) in GaAs/AIGaAs-heterostructures in the magnetic quantum limit using a high-sensitive superconducting susceptometer. In particular we have studied the magnetization at filling factor ν=1, where the 2DES forms the quantum Hall ferromagnet. We extract from our data that the orbital magnetic moment is strongly enhanced at low temperatures T by spin-dependent exchange effects. Temperature dependent measurements show

Neutron scattering study of the field-induced soliton lattice in CuGeO3

Chat with Graph Search

Effect of Magnetic Field on Dynamics of Antiferromagnets

Bismuth Micro and Nano Hall Sensors on Photo-plastic Cantilevers for Scanning Hall Probe Microscopy

Numerical Analysis of the Effects of the Magnetic Self-Field on the Transport Properties of a Multilayer HTS Cable

Evidence for an incommensurate magnetic resonance in La2-xSrxCuO4

Dynamics of magnetically retained supraparticle structures in a liquid flow

Planar coil-based microsystem for the long-range transport of magnetic beads

DC behaviour of NbTi cable-in-conduit conductors for ITER-FEAT

Car-Parrinello Molecular Dynamics in a Finite Homogeneous Electric Field

Integrated planar fluxgate sensor

Geometry considerations for transport current applications of Bi-2223 conductors with anisotropic Jc(B) in external magnetic field

Indoor radiated emission associated with power line communication systems

Spin-dependent exchange and correlation effects on the orbital magnetization of two-dimensional electron systems