WANNIER FORMULATION OF THE LEE-LOW-PINES TRANSFORMATION
Matthias Rapp, M Wagner · Proceedings of the Estonian Academy of Sciences Physics Mathematics · 1995
A 2nd quantized version of the Lee-Low-Pines transformation (LLPT) is prcsented in a one-band Wannier base which offers itself to multiparticle applications.It is first applied (o a trans- lationally invariant coupled electron-phonon system.Later it is generalized to arbitrary Abclian Hamiltonians.In the one-electron case the transformation achieves diagonalization of the respec- tive Hamiltonians with regard to the electronic subspace.This is even achieved in the case when the clectron-phonon intcraction is nonlincar.Also, in a multiparticle case the LLPT can be fully performed.An illustrative example is given.For future application it may further be noted that the multiparticle LLPT establishes cffective clectron-clectron interaction terms of non-Frohlich type, which may also have an impact onto superconductivity.