M. Sardar, PHONON SOFTENING IN BILAYER CUPRATE SUPERCONDUCTORS DUE TO INTERLAYERPAIR TUNNELING, Physica. C, Superconductivity, 298(3-4), 1998, pp. 254-264
The anomalous phonon mode softening observed in the superconducting ph
ase in inelastic neutron scattering experiments is shown to occur due
to the interlayer pair tunnelling mechanism of Wheatley et al. [Phys.
Rev. B 37 (1988) 5897]. We show the emergence of a novel supercurrent
phonon coupling in Josephson coupled superconducting layers. Differenc
e in phonon frequency shifts for the A(g) and A(u) Raman active modes
are shown to have a natural explanation within this mechanism. Frequen
cy softening mechanisms for Raman and infrared phonons, in both normal
and superconducting state are discussed. (C) 1998 Elsevier Science B.
V.