Laurent Proville

Biphonons in the Klein-Gordon lattice

A numerical approach is proposed to compute the quantum eigenmodes of a nonlinear Klein-Gordon lattice. In agreement with other studies on different lattices, nonlinearity is found to lead to a phonon pairing and consequently some biphonon excitations. The energy branch and the correlation properties of the Klein-Gordon biphonon are studied in detail.

Depinning transition for a screw dislocation in a model solid solution

On the basis of the classical dislocation theory, the solid solution hardening (SSH) is commonly ascribed to the pinning of the edge dislocations. At the atomic level, the theoretical study of the dislocation cores contrasts with such a prediction. Using the static molecular simulations with some interatomic effective potentials, we demonstrate numerically that the critical resolved shear stress associated with a screw dislocation in a random Ni(Al) single crystal has the same order as the edge one. Such a result is imposed by the details of the dislocation stacking fault and the core dissociation into Shockley partials. The SSH statistical theory is employed to tentatively predict analytically the data acquired through our atomistic simulations at different Al concentration.

Atomic-scale study of dislocation glide in a model solid solution

Based on atomic-scale simulation techniques, we study the dislocation pinning mechanism in a dilute Ni(Al) model solid solution. For a solute concentration between 1 and 10 at.% , we found that the pinning of the dislocation on obstacles made of Al pairs is an interaction that operates significantly. The statistics of the dislocation motion is then modified accordingly to the nature of the obstacles and follows modified Mott–Nabarro statistics. Finally, a method to address thermal activation is proposed and exemplified on a periodic row of solute pairs.

Kinetics of the coherent order-disorder transition in Al 3 Zr

Within a phase field approach which takes the strain-induced elasticity into account, the kinetics of the coherent order-disorder transition is investigated for the specific case of

Small bipolarons in the 2-dimensional Holstein-Hubbard model. I. The adiabatic limit

{\mathrm{Al}}_{3}\mathrm{Zr}

Quantum breathers in a nonlinear Klein Gordon lattice

alloy. It is shown that a microstructure with cubic

Mobile bipolarons in the adiabatic Holstein-Hubbard model in one and two dimensions

{L1}_{2}

Self-organization of (001) cubic crystal surfaces

precipitates appears as a transient state during the decomposition of a homogeneous disordered solid solution into a microstructure with tetragonal

Dislocation pinning by substitutional impurities in an atomic-scale model for Al(Mg) solid solutions

{\mathrm{DO}}_{23}

Dynamical structure factor of a nonlinear Klein-Gordon lattice

precipitates embedded into a disordered matrix. At low enough temperature, favored by a weak internal stress, only