When a flat wave enters the medium along the z-axis so that at t = 0 the initial

wave vector is everywhere equal to k(0) = [k.

9 (14), at a single setting of the spectrometer centered at a

wave vector of (1/4,1/4, 0) and energy transfer of 10 meV.

We measured the

wave vector and damping coefficient at the frequency between 50 and 1000 Hz.

0] is the total number of charged sound particles at the condensate level with the

wave vector [?

where [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] is the average number of Bose quasiparticles with spin 1 with the

wave vector k at the temperature T:

64, -1 >) values of angles between directions of main T wave and R

wave vectors were determined according to Kardys et al.

t] are the unknown constants which are found as below; [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] are, respectively, the Bose vector-operators of creation and annihilation of electric fields of one ion-wave particle with

wave vector [?

0,t] is the total number of Sound Particles in the condensate level with

wave vector [?

Each Fourier transform F(Q) equals the volume integral [8] of the respective [rho](r)exp(-iQ * r), Q denoting the

wave vector transfer.

is the density operator of the electron modes with

wave vector [?

Conservation of the tangential component of the neutron

wave vector across the interface yields the exact phase

For our interference simulations in the plane wave theory, we extended our previous program [4] prepared with the decomposition of the

wave vector to the parallel and the perpendicular components to the sample surface.