We generalize the concept of quasiparticle for one-dimensional (1D) interacting electronic systems. The ↑ and ↓ quasiparticles recombine the pseudoparticle colors c and s (charge and spin at zero magnetic field) and are constituted by one manypseudoparticle topological momenton and one or two pseudoparticles. These excitations cannot be separated. We consider the case of the Hubbard chain. We s...

Using the one-loop functional renormalization group technique, we evaluate the self-energy in the weak-coupling regime of the 2D t-t(') Hubbard model. At van Hove (vH) band fillings and at low temperatures, the quasiparticle weight along the Fermi surface (FS) continuously vanishes on approaching the (pi,0) point where the quasiparticle concept is invalid. Away from vH band fillings the quasipa...

We performed angle-resolved photoemission experiments on overdoped single crystal Bi 2 Sr 2 CaCu 2 O 8+x samples with Tc values as low as 55K and very narrow transitions as measured by AC susceptibility. The photoemission data indicate the presence of a " shadow " peak in the quasiparticle spectral function A(ω) shifted by (π, π) from the conventional quasiparticle peak. The ratio of the shadow...

On the basis of the Kadanoff-Baym (KB) version of the time-dependent Green’s function method a new ansatz for the approximation of a spectral function is offered. The ansatz possesses all the advantages of quasiparticle (QP) and extended quasiparticle (EQP) approximations and satisfies the KB-equation for a spectral function in the case of slightly non-equilibrium system when disturbances in sp...

We show that a small number of intentionally introduced defects can be used as a spectroscopic tool to amplify quasiparticle interference in 2H-NbSe2 that we measure by scanning tunneling spectroscopic imaging. We show, from the momentum and energy dependence of the quasiparticle interference, that Fermi surface nesting is inconsequential to charge density wave formation in 2H-NbSe2. We demonst...

We have computed the quasiparticle wave function corresponding to a hole injected in a triangular antiferromagnet. We have taken into account multi-magnon contributions within the self consistent Born approximation. We have found qualitative differences, under sign reversal of the integral transfer t, regarding the multi-magnon components and the own existence of the quasiparticle excitations. ...

The Josephson quasiparticle (JQP) cycle in a voltage-biased superconducting single-electron transistor (SSET) combines coherent Cooper pair tunneling with incoherent quasiparticle decay. We have measured the influence of current flow through an independently-biased SSET on the JQP cycle when the two SSET’s have a strong mutual capacitive coupling. We find, among other effects, that the JQP curr...

We study the nonlinear transport properties of NS (normal-superconductor) and NSN structures by means of a self-consistent microscopic description. A nonzero superfluid velocity causes the various quasiparticle channels within S to open at different voltages. The gap reduction is very sensitive to the details of quasiparticle scattering. At low temperatures, superconductivity, some times in a p...

A state with 2 electons has a charge of 1/2. The states of 3 electrons have quasiparticle charge of 4/11 and 5/13; the one with 5 electrons have quasiparticle charges 4/13 and 6/17. The state with 7 electrons exhibits quasiparticle charges of 5/17 and 12/17. When spin is reversed, the charge of three particle state changes from 4/11 to 7/11. These predicted results agree with the recent experim...