22 Result(s)

Article

Anharmonic Effects in Neutron Scattering Studies of Lattice Excitations in BCC ⁴He

We report high resolution measurements of lattice excitations of bcc solid ⁴He using inelastic neutron scattering. The resulting dispersion relations of the phonons agree well with Path Integral Monte Carlo Simul...

O. Pelleg, J. Bossy, E. Farhi, M. Shay, V. Sorkin… in Journal of Low Temperature Physics (2008)

Article

Dynamics of quantum liquids in confinement, theory and experiment

Liquid ⁴He immersed in porous media such as aerogel, Vycor, and Geltech silica are excellent examples of bosons in disorder and confinement. Of special interest is the impact of disorder on Bose-Einstein condensa...

H. R. Glyde, F. Albergamo, R. T. Azuah, J. Bossy, B. Fåk in The European Physical Journal E (2003)

Article

Measurement and simulation of the inelastic resolution function of a time-of-flight spectrometer

The deconvolution of inelastic neutron scattering data requires the knowledge of the inelastic resolution function. The inelastic resolution function of the time-of-flight spectrometer IN5/ILL has been measure...

S.V. Roth, A. Zirkel, J. Bossy, J. Neuhaus, J. Peters, H. Schober… in Applied Physics A (2002)

Article

Inelastic Neutron Scattering Studies of First Order Phase Transitions in bcc Solid ⁴He

We report inelastic neutron scattering studies of the [110] transverse phonon branches of bcc ⁴He near the bcc-hcp transitions on the solid-liquid coexistence line and near the melting transition. The question be...

T. Markovich, E. Polturak, S. G. Lipson, J. Bossy… in Journal of Low Temperature Physics (2002)

Article

Phonon dispersion of bcc cerium

The phonon dispersion of the high temperature bcc or δ-phase of cerium has been measured by inelastic neutron scattering, growing the single crystals in situ on the spectrometer. The phonon dispersion shows a cha...

K. Nicolaus, J. Neuhaus, W. Petry, J. Bossy in The European Physical Journal B - Condense… (2001)

Chapter

Magnetic Resonance Peak and Nonmagnetic Impurities

Nonmagnetic Zn impurities are known to strongly suppress superconductivity. We review their effects on the spin excitation spectrum in YB_a2Cu₃O₇, as investigated by inelastic neutron scattering measurements.

Y. Sidis, P. Bourges, B. Keimer… in Open Problems in Strongly Correlated Elect… (2001)

Article

Excitations and Their Temperature Dependence in Superfluid ⁴He Beyond the Roton

The temperature dependence of the dynamic structure factor S(Q,ω) for superfluid ⁴ He has been measured by inelastic neutron scattering for wave vectors between 2.3 and 2.6 Å ^−l. S(Q,ω) has two peaks: one sharp ...

B. Fåk, J. Bossy in Journal of Low Temperature Physics (1998)

Article

Temperature Dependence of S(Q, E) in Liquid ⁴He Beyond the Roton

The temperature dependence of the dynamic structure factor S(Q, E) for superfluid and normal liquid ⁴ He at saturated vapor pressure has been measured by inelastic neutron scattering for wave vectors Q between 2...

B. Fåk, J. Bossy in Journal of Low Temperature Physics (1998)

Article

Thermodynamic Properties of Multilayer ³He Films Described by High Temperature Series Expansions of the Multiple Spin Exchange Hamiltonian

We report high precision NMR measurements of the susceptibility of ³ He films adsorbed on graphite in a the temperature range 4-300 mK using a fine coverage grid between 0.185 and 0.285 atoms/Å ². High temperatu...

C. Bäuerle, J. Bossy, Yu. M. Bunkov, A.-S. Chen… in Journal of Low Temperature Physics (1998)

Article

Spin dynamics by inelastic neutron scattering in YBCO

Key features of Inelastic neutron scattering experiments in YBCO-based cuprates are discussed. We underline the importance of precise oxygen content determination in samples having similar T_C as well as the resol...

P. Bourges, L. P. Regnault, Y. Sidis, J. Bossy… in Journal of Low Temperature Physics (1996)

Article

X-Ray and neutron scattering studies of YBa₂Cu₃O_6+x compounds: Oxygen insertion and spin dynamics

In the first part of this paper the results of X-ray and neutron diffraction studies of the structural aspects related to oxygen insertion in the CuO _x planes of YBa₂Cu₃O_6+x co...

P. Burlet, P. Bourges, J. Bossy, E. Elkaim, J. Y. Henry… in Journal of Superconductivity (1996)

Article

The new grenoble 100 μK refrigerator

We describe the design and performance of the ultra-low temperature refrigerator recently built at Grenoble. So far we have used both a “Lancaster type” and a “Laminar type” of nuclear demagnetization stage. T...

C. Bäuerle, J. Bossy, Yu. M. Bunkov, S. N. Fisher… in Czechoslovak Journal of Physics (1996)

Article

High-resolution measurements of rotons in⁴He

We have measured the temperature dependence of the roton line shape (energy and width) using neutron backscattering. An energy resolution of less than 1 μeV was obtained, allowing a determination of the roton ...

K. H. Andersen, J. Bossy, J. C. Cook in Czechoslovak Journal of Physics (1996)

Article

2D liquid³He near solidification: a highly correlated Fermi liquid

The magnetic susceptibility of two-dimensional liquid³He adsorbed on graphite has been measured by NMR techniques for submonolayer and second layer coverages in a large temperature range around the Fermi temperat...

K. -D. Morhard, C. Bäuerle, J. Bossy, Yu. Bunkov… in Journal of Low Temperature Physics (1995)

Article

NMR of adsorbed³He: Surface physics at millikelvin temperatures

NMR techniques are used for the study of two-dimensional quantum systems, represented by³He physically adsorbed on Grafoil, an exfoliated form of graphite. A description of our high sensitivity and very low power...

K. -D. Morhard, J. Bossy, Ch. Bäuerle, J. P. Faure… in Applied Magnetic Resonance (1995)

Article

Mobility of the³He crystal-liquid interface at the minimum of the melting curve

Measurements of the mobility of the³He liquid-crystal interface at the minimum of the melting curve are presented. The experiments show a clear asymmetry in the mobility for high melting and growing velocities of...

J. Amrit, J. Bossy in Journal of Low Temperature Physics (1993)

Article

Excitations in liquid⁴He beyond the roton

The dynamic structure factor S(Q,E) for liquid⁴He at saturated vapor pressure has been measured by inelastic neutron scattering for wave vectors Q between 1.9 and 2.8 Å⁻¹. The temperature dependence is studied fo...

B. Fåk, L. P. Regnault, J. Bossy in Journal of Low Temperature Physics (1992)

Article

Neutron experiments on solid³He in high field at very low temperature

The magnetic transition from the paramagnetic phase to the magnetically ordered high-field phase of solid³He is observed by polarized neutron transmission experiments. The transition shows the feasibility of neut...

J. Bossy, A. Benoit, J. Schweizer in Journal of Low Temperature Physics (1990)

Article

Books received

JPC, J-H Neidhardt, J Bossy in Surgical and Radiologic Anatomy (1986)

Article

Crystal growth of solid³He

Crystal growth of³He in restricted and bulk geometries is described. A striking feature is the growth of single crystals inside a metallic power of 0.3 µm mean grain size. Comparison of the intensity of the (1, 1...

J. Bossy, A. Benoit, J. Flouquet, J. Schweizer in Journal of Low Temperature Physics (1986)