ar X iv : c on d - m at / 9 80 60 22 v 1 2 J un 1 99 8 Lattice Dimerization in the Spin - Peierls Compound CuGeO 3

ar X iv : c on d - m at / 9 60 31 85 v 1 2 8 M ar 1 99 6 New phase diagram of Zn - doped

A series of high-quality single crystals of Cu 1−x Zn x GeO 3 have been examined by neutron scattering techniques. An antiferromagnetic (AF) ordering is confirmed for samples with x ≥ 0.02, in complete agreement with previous reports. We show that the spin-Peierls (SP) phase transition persists to 6% Zn, whereas previous magnetic susceptibility measurements reported a deterioration of the SP tr...

ar X iv : c on d - m at / 9 80 60 82 v 1 [ co nd - m at . m tr l - sc i ] 5 J un 1 99 8 Magnetic Particles

Electron - phonon and spin - phonon coupling in NaV 2 O 5 : charge fluctuations effects

(received ; accepted) PACS. 63.20Kr – Phonon-electron and phonon-phonon interactions. PACS. 75.30Et – Exchange and superexchange interactions. PACS. 78.30−j – Infrared and Raman spectra. Abstract. – We show that the asymmetric crystal environment of the V site in the ladder compound NaV2O5 leads to a strong coupling of vanadium 3d electrons to phonons. This coupling causes fluctuations of the c...

ar X iv : c on d - m at / 9 51 21 60 v 1 2 2 D ec 1 99 5 Spin - reflection positivity of the Kondo lattice at half - filling

We examine the spin-reflection positivity of the ground state of the Kondo lattice model at half-filling with the antiferromagnetic and ferromagnetic exchange couplings J = 0. For every positive U > 0, where U is the Coulomb interaction between the conduction electrons, we can show that the ground state is unique.

ar X iv : c on d - m at / 9 80 60 43 v 1 3 J un 1 99 8 Electrodymanics with Toroid Polarization

A modified system of equations of electrodynamics has been obtained. Beside the Lagrangian one an alternative gauge-like formalism has been developed to introduce the toroid moment contributions in the equations obtained. The two potential formalism that was worked out by us earlier has been developed further where along with the two vector potentials we introduce two scalar potentials thus tak...