Q-Ball Mechanism of Electron Transport and SPIN/Lattice Excitations Properties of High-Tc Superconductors

Abstract

Abstract

The Q-ball mechanism of high-Tc superconductivity in cuprates, recently proposed by the author, is farther explored. Euclidean Q-balls are Bose condensed spin/charge density wave fluctuations (SDW/CDW) with zero static mean that arise simultaneously with Cooper/local pairs superconducting condensate for which they serve as the ’pairing glue’. Bose condensates of SDW/CDW fields possess wave-vectors connecting ’nested’ parts of the Fermi surface near van Hove singularities causing pairing of the fermionic states into superconducting Bose condensates. Self-consistency equations for quantum orders periodic in the imaginary Matsubara time fields signify a new development beyond Landau static mean-field order parameter approach. Cooper/local pairs condensation lowers Q-balls total energy relative to not condensed thermal SDW/CDW fluctuations in the same volume. Q-balls’ superconducting condensates cause spectral gap on the nested parts of the Fermi surface in the ’pseudogap’ phase of high-Tc cuprates, where the Q-ball scenario was supported by micro X-ray diffraction data in HgBa2CuO4+y. Scattering on the Q-balls causes: T-linear growth of electrical resistivity, splitting of in-plane phonon brunches into softened and hardened ones and "hourglass" dispersion of spin-wave excitations close to CDW and SDW wave vectors respectively. Diamagnetic response of Q-balls’ gas above Tc is in qualitative accord with experimental data in high-Tc cuprates.