相关论文: Dynamical Properties of a Single Hole in an Antife…
It is shown that the dynamics of a single hole in a quantum antiferromagnet (described by the t--J model) can be simply understood in terms of a composite quasiparticle. This description provides naturally two different energy scales t and…
The dynamics of a single hole in quantum antiferromagnets is influenced by magnetic fluctuations. In the present work we consider two situations. The first one corresponds to a single hole in the two leg t-J spin ladder. In this case the…
We have analyzed the dynamics of a single hole doped in a canted antiferromagnet using the t-J model. Within the self consistent Born approximation we have found that the hole propagates at two different energy scales along the…
The quasi-particle weight of a single hole in an antiferromagnetic background is studied in the semiclassical approximation. We start from the t-J model, generalize it to arbitrary spin S by employing an appropriate coherent state…
The motion of a single hole in a 2D triangular antiferromagnet is investigated using the t-J model. The one-hole states are described by strings of spin deviations around the hole. Using projection technique the one-hole spectral function…
Clusters of the two-dimensionnal t--J model with 2 holes and up to 26 sites are diagonalized using a Lanczos algorithm. The behaviour of the binding energy with system size suggests the existence of a finite critical value of J above which…
We develop an efficient numerical method for the description of a single-hole motion in the antiferromagnetic background. The method is free of finite-size effects and allows calculation of physical properties at an arbitrary wavevector.…
The evolution of hole and spin dynamics in high temperature superconductors is studied within the self-consistent noncrossing approximation of the t-J model in the small hole density limit. As the doping concentration is increased,…
We study the hole and magnon spectral functions as a function of hole doping in the two-dimensional (2D) t-J and t-t'-t"-J models working within the limits of the spin-wave theory, by linearizing the hole-spin-deviation interaction and by…
The T=0 phase diagram of the planar t--J model with small doping is investigated by exact diagonalisations of square clusters with up to 32 sites. At half-filling, the single hole quasi-particule weight vanishes in the strong correlation…
We investigate the dynamics of a single hole coupled to the spiral fluctuations related to the magnetic ground states of the antiferromagnetic J_1-J_2-J_3 Heisenberg model on a square lattice. Using exact diagonalization on finite size…
The t-J_z model is the strongly anisotropic limit of the t-J model which captures some general properties of the doped antiferromagnets (AF). The absence of spin fluctuations simplifies the analytical treatment of hole motion in an AF…
The motion of a single hole in an arbitrary magnetic background is investigated for the 2D t-J model. The wavefunction of the hole is described within a generalized string picture which leads to a modified concept of spin polarons. We…
The two-layer square lattice quantum antiferromagnet with spins 1/2 shows a magnetic order-disorder transition at a critical ratio of the interplane to intraplane couplings. We investigate the dynamics of a single hole in a bilayer…
Exact diagonalization numerical results are presented for a 32-site square cluster, with two holes propagating in an antiferromagnetic background described by the t-J model. We characterize the wave function of the lowest energy bound state…
The energy of one hole in one dimensional Ising antiferromagnet is calculated using exact diagonalization (ED) method on finite systems with number of sites N ranging from 4 to 50. This study gives a power-law description for the hole…
We study the effect of hole hopping in a doped antiferromagnet described by the `t-J' model, using exact analytic solutions for small clusters. In spite of the small size, they reveal interesting details about the magnetic order, which are…
We study the motion of holes in a mixed-dimensional setup of an antiferromagnetic ladder, featuring nearest neighbor hopping $t$ along the ladders and Ising-type spin interactions along, $J_\parallel$, and across, $J_\perp$, the ladder. We…
We present results of an exact diagonalization calculation of the spectral function $A(\bf k, \omega)$ for a single hole described by the $t$--$J$ model propagating on a 32--site square cluster. The minimum energy state is found at a…
We review in details a recently proposed technique to extract information about dynamical correlation functions of many-body hamiltonians with a few Lanczos iterations and without the limitation of finite size. We apply this technique to…