Beta Irradiation of a Geometrically Metastable Superconducting Strip Detector with a Magnetic Flux Penetration Read-Out

Geometrical metastability, observed in superconducting type I tin flat strips, has been previously proposed as a principle for particle detection. The energy deposition of an incoming beta-particle induces the rupture of the metastability and consequently the penetration of multiquantum flux tubes into a superconducting tin strip. We present here the first absorption spectra from two beta sources, which demonstrate the linearity and energy-resolution of these detectors (presented at the 6th International Workshop on Low Temperature Detectors for Dark Matter and Neutrinos (LTD-6), Interlaken, Switzerland, Sept. 1995)Comment: Compressed PostScript (filename.ps.Z), 8 pages, 2 figure

Coupling of replicate order-parameters in incommensurate multiferroics

The specific properties of incommensurate multiferroic phases resulting from the coupling of order-parameter replicates are worked out using the illustrative example of iron vanadate. The dephasing between the order-parameter copies induces an additional broken symmetry phase corresponding to the lowest symmetry of the system and varies critically at the transition to the multiferroic phase. It reflects the temperature dependence of the angle between paired spins in the antiferromagnetic spiral structure. Expressing the transition order-parameters in terms of spin-density waves allows showing that isotropic exchange interactions contribute to the stabilization of the ferroelectric phase

Interactions diamagnetiques et irradiation X d'un composite de microbilles d'etain en surchauffe supraconductrice

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Phenomenological theory of the formation of cubic phases in complex fluids

A unifying phenomenological model is proposed, which describes the cubic meso phases found in complex fluid systems. The order-parameter symmetries associated with the formation mechanism of the mesophases are determined. The different configurations associated with the same cubic symmetry are described in the case of the gyroïd phase

Theory of the non-planar surface phase in tilted smectic films under electric field

We present a phenomenological theory of the non-planar tilted surface phase recently observed in freely suspended smectic films. We show that the three phases —Synclinic, Anticlinic, and non-planar (Axial)— stable in non-chiral systems, merge into a single phase in chiral systems. We discuss some experimental consequences of this specific chiral feature. We predict the effects of electric field application parallel to the smectic layers on the stability of the various zero-field surface phases, and determine the conditions for the observation of field-induced chiral Anticlinic/Synclinic crossovers. In thin films they depend only on the ratio between the bulk electroclinic coupling energy and the surface electric-field-tilt coupling