Related papers: Mapping spin-charge separation without constraints
The question of spin-charge separation in two-dimensional lattices has been addressed by numerical simulations of the motion of one hole in a half-filled band. The calculations have been performed on finite clusters with Hubbard and t-J…
Quasiparticle properties are explored in an effective theory of the $t-J$ model which includes two important components: spin-charge separation and unrenormalizable phase shift. We show that the phase shift effect indeed causes the system…
Spin-charge separation is a hallmark of one-dimensional fermionic systems, yet its realization in higher dimensions remains an open question. To address this issue, we investigate a two-leg t-J ladder using the density matrix…
A spin-charge recombination route to superconductivity, proposed earlier (1992)], is examined using the Schwinger boson representation of the t-J model. The representation is known to work well at half-filling. It was shown in the earlier…
We revisit the Jordan-Wigner transformation, showing that --rather than a non-local isomorphism between different fermionic and spin Hamiltonian operators-- it can be viewed in terms of local identities relating different realizations of…
In this paper we study a generalization of the 1D Hubbard model by considering density-density and Ising-type spin-spin nearest neighbor (NN) interactions, parameterized by $V$ and $J$, respectively. We present the T=0 phase diagram for…
We show that the t-J Hamiltonian is not in general reduced to H(S,f), where S and f stand for independent ([S,f]=0) SU(2) (spin) generators and spinless fermionic (hole) field, respectively. The proof is based upon an identification of the…
I show that spin-charge separation in 2-D t-J model leads to an increase of kinetic energy. Using a sum rule, I derive an exact expression for the lowest possible KE (E_{bound}) for any state without doubly occupied sites. KE of relevant…
A local transformation from fermionic operators to spin matrices is proposed and studied in this work. For this purpose, a system of fermions on a lattice is considered and one applies the scheme to replace the fermionic variables with spin…
In this paper a description of the energy eingenstates of the Hubbard model on the square lattice with nearest-neighbor transfer integral $t$, on-site repulsion $U$, and $N_a^2\gg 1$ sites in terms of occupancy configurations of charge $c$…
We consider the repulsive Hubbard model in one dimension and show the different mechanisms present in the charge and spin separation phenomena for an electron, at half filling and bellow half filling. We also comment recent experimental…
In this paper a description of the Hubbard model on the square lattice with nearest-neighbor transfer integral $t$, on-site repulsion $U$, and $N_a^2\gg 1$ sites consistent with its exact global $SO(3)\times SO(3)\times U(1)$ symmetry is…
The impact of the spin-flip terms on the (static and dynamic) charge and spin correlations in the Luttinger-liquid ground state of the 1D $t-J$ model is assessed by comparison with the same quantities in the 1D $t-J_z$ model, where…
Elementary particles such as the electron carry several quantum numbers, for example, charge and spin. However, in an ensemble of strongly interacting particles, the emerging degrees of freedom can fundamentally differ from those of the…
A spin-charge unifying description for the Hubbard model based on the time dependent local gauge transformations is developed. The collective variables for charge and spin are isolated in the form of the space-time fluctuating U(1) phase…
In this paper the spin configurations of the ground state and one- and two-electron excited states of the Hubbard model on the square lattice are studied. We profit from a general rotated-electron description, which is consistent with the…
The spin and charge excitations of the t--J ladder are studied by exact diagonalization techniques for several electron densities. The various modes are classified according to their spin (singlet or triplet excitations) and their parity…
We consider a spin coherent states description of a general quantum spin system. It is shown that it is possible to use the spin-1/2 representation to study the general spin-J case. We identify the 1/2 spinor components as the homogeneous…
The $t$-model represents the Hubbard model in the limit $U \to \infty$ and is one of the basic models of strongly correlated electrons. On a one-dimensional chain, the model is integrable, and the charge dynamics corresponds to that of free…
We propose a trajectory-based method for simulating nonadiabatic dynamics in molecular systems with two coupled electronic states. Employing a quantum-mechanically exact mapping of the two-level problem to a spin-1/2 coherent state, we…