Ho<Subscript>0.1</Subscript>Ca<Subscript>0.9</Subscript>MnO<Subscript>3</S ubscript> is a canted antiferromagnet with the magnetic space group Pn′ma′. The magnetic structure is a superposition C<Subscript> x </Subscript>F<Subscript> y </Subscript>A<Subscript> z </Subscript> of the three types of order allowed in Pn′ma′. In the Ca-rich corner of the system Ho<Subscript>1−x </Subscript>Ca<Subscript> x </Subscript>MnO<Subscript>3</Subscript> the title compound has a strong magnetoelastic...</subscript></subscript></subscript></subscript></subscript></subscript><//s></subscript></subscript></subscript>

The spatially localized bound states of two electrons in the adiabatic two-dimensional Holstein-Hubbard model on a square lattice are investigated both numerically and analytically. The interplay between the electron-phonon coupling g, which tends to form bipolarons and the repulsive Hubbard...

The Feynman-Haken variational path integral theory is, for the first time, generalized to calculate the ground-state energy of an electron coupled simultaneously to a Coulomb potential and to a longitudinal-optical (LO) phonon field in parabolic quantum wires. It is shown that the polaronic...

We investigate polaron formation in a many-electron system in the presence of a local repulsion sufficiently strong to prevent local-bipolaron formation. Specifically, we consider a Hubbard-Holstein model of interacting electrons coupled to dispersionless phonons of frequency ω <Subscript>0</Subscript>. Numerically...</subscript>