Related papers: Antiferromagnetic systems with spin gap: exact res…
We study a one-dimensional electron liquid coupled by a weak spin-exchange interaction to an antiferromagnetic spin-S ladder with n legs. A perturbative renormalization group analysis in the semiclassical limit reveals the opening of a spin…
Complexity in materials often arises from competing interactions at the atomic length scale. One such example are the strongly correlated heavy-fermion materials where the competition between Kondo screening and antiferromagnetic ordering…
In this paper several examples of gaps (lacunes) between dimensions of maximal and submaximal symmetric models are considered, which include investigation of number of independent linear and quadratic integrals of metrics and counting the…
A theory is proposed to describe the competition among antiferromagnetism (AF), spin glass (SG) and Kondo effect. The model describes two Kondo sublattices with an intrasite Kondo interaction strength $J_{K}$ and a random Gaussian…
By explicitly tracking the Marshall sign, a phase string induced by hopping is revealed in the one-hole-doped $t-J$ model. It is rigorously shown that such a phase string cannot be eliminated through low-lying spin excitations, and it…
On the basis of Quantum Monte Carlo simulations of the two-dimensional Hubbard model which cover the doping range from the under- to the over-doped regime, we find that the single-particle spectral weight $A (\vec k,\omega)$ qualitatively…
In doped two-leg spin ladder systems, holes are expected to form charged bosonic pairs. We study charge transport in this system in the temperature range where the bosons can be described as weakly interacting quasi-particles. We consider…
In the presence of nonlocal phase shift effects, a quasiparticle can remain topologically stable even in a spin-charge separation state due to the confinement effect introduced by the phase shifts at finite doping. True deconfinement only…
A lithium dopant in a cuprate spin ladder acts as a vacant (non-magnetic) site accompanied by an extra hole bound by a Coulomb potential. We find that, although the undoped ladder spin gap is not essentially altered by Li doping, a…
We present an analytic theory for the energy spectrum of a two-leg spin ladder doped with two holes. Starting from a pseudo-fermion-bond-boson representation of the corresponding $t_{1,2}-J_{1,2}$ Hamiltonian we apply a diagrammatic…
We discuss the recent progress and the current status of experimental investigations of spin-mediated energy transport in spin-chain and spin-ladder materials with antiferromagnetic coupling. We briefly outline the central results of…
We present an analytically solvable model for correlated electrons, which is able to capture the major Fermi surface modifications occurring in both hole- and electron-doped cuprates as a function of doping. The proposed Hamiltonian…
We study theoretically the spin transport in a nonmagnetic metal connected to ferromagnetic injector and detector electrodes. We derive a general expression for the spin accumulation signal which covers from the metallic to the tunneling…
The competition between different forms of order is central to the problem of strong correlation. This is particularly true of frustrated systems, which frequently exist at or near to a zero-temperature critical point. Here we show that a…
Hole-doping effects are investigated on the {\it t-J} ladder model with the linked-tetrahedra structure. We discuss how a metal-insulator transition occurs upon hole doping with particular emphasis on the effects of geometrical frustration.…
The mechanism of the pseudogap observed in hole-doped cuprates remains one of the central puzzles in condensed matter physics. We analyze this phenomenon via a Feynman-diagrammatic inspection of the Hubbard model. Our approach captures the…
The emergence of quasiparticles in quantum many-body systems underlies the rich phenomenology in many strongly interacting materials. In the context of doped Mott insulators, magnetic polarons are quasiparticles that usually arise from an…
Antiferromagnets offer an attractive platform for spintronics due to their absence of net magnetization and ultrafast spin dynamics, yet their intrinsically spin-compensated electronic structure has traditionally limited their active role…
We establish exact results for the one-dimensional spin-orbital model for special values of the four-spin interaction $V$ and dimerization parameter $\delta$. The first exact result is at $\delta=1/2$ and $V=-2$. Because we find a very…
We investigate the properties of the electron spin-transmission through an Aharonov-Bohm interferometer with an embedded multilevel quantum dot containing magnetic impurities. A suitable formalism is developed. The amplitude and the phase…