In this paper, we study persistent charge and spin currents in the ground state of the one-dimensional mesoscopic Hubbard ring with repulsive interaction based on its Bethe-ansatz solution. We find that the persistent charge current is suppressed by the on-site Coulomb interaction more significantly at half-filling than away from half-filling. As the system size increases the charge current decays exponentially as I ∼ L −1 e − L /ξ in the half-filling case and decays in a power law away from the half-filling case. We also find that the persistent spin current is suppressed by the on-site Coulomb interaction, and it decays algebraically as the system size increases both at half-filling and away from half-filling.In this paper, we study persistent charge and spin currents in the ground state of the one-dimensional mesoscopic Hubbard ring with repulsive interaction based on its Bethe-ansatz solution. We find that the persistent charge current is suppressed by the on-site Coulomb interaction more significantly at half-filling than away from half-filling. As the system size increases the charge current decays exponentially as I ∼ L −1 e − L /ξ in the half-filling case and decays in a power law away from the half-filling case. We also find that the persistent spin current is suppressed by the on-site Coulomb interaction, and it decays algebraically as the system size increases both at half-filling and away from half-filling.

Journal of Physics Condensed MatterSep 1, 200813 citations

Charge currents of spin excitations in one-dimensional Hubbard model

S. Brazovskiǐ, F. Matveenko, Ph. Nozières

Nov 1, 19933 citations

Spin operators beyond the Heisenberg limit of the half-filled Hubbard model

Jean-Yves P. Delannoy, Michel J. P. Gingras, P. C. W. Holdsworth +1 more

Dec 1, 20040 citations

Persistent currents and spin-charge separation in a one-dimensional Hubbard ring with side sites

W. Z. Wang

The persistent current and spin-charge separation are studied in a one-dimensional (1D) Hubbard ring with side sites connected to the even sites of the ring. At half filling, the persistent current is always paramagnetic and has a period of flux quantum. Away from half filling, as the onsite repulsion $U$ increases, the sign of the current may oscillate depending on the total number of electrons ${N}_{e}$ and the hopping $t$ between the ring site and the side site. For small hopping $t$ , the number of electrons ${N}_{e}^{\ensuremath{'}}$ in the ring sites plays an important role in determining the sign of the current. In contrast to the 1D Hubbard model, a weak or a moderate $U$ can strongly enhance the persistent current while the hopping $t$ always suppresses the current. The study on the transmittance of the ring with two connected leads indicates that in the large $U$ and small $t$ case, the transmittance varies with a period $1∕{N}_{e}^{\ensuremath{'}}$ of a flux quantum, demonstrating a spin-charge separation in this system.The persistent current and spin-charge separation are studied in a one-dimensional (1D) Hubbard ring with side sites connected to the even sites of the ring. At half filling, the persistent current is always paramagnetic and has a period of flux quantum. Away from half filling, as the onsite repulsion $U$ increases, the sign of the current may oscillate depending on the total number of electrons ${N}_{e}$ and the hopping $t$ between the ring site and the side site. For small hopping $t$, the number of electrons ${N}_{e}^{\ensuremath{'}}$ in the ring sites plays an important role in determining the sign of the current. In contrast to the 1D Hubbard model, a weak or a moderate $U$ can strongly enhance the persistent current while the hopping $t$ always suppresses the current. The study on the transmittance of the ring with two connected leads indicates that in the large $U$ and small $t$ case, the transmittance varies with a period $1∕{N}_{e}^{\ensuremath{'}}$ of a flux quantum, demonstrating a spin-charge separation in this system.

Physical Review BFeb 6, 20073 citations

Strange behavior of persistent currents in small Hubbard rings

Santanu K. Maiti, Jayeeta Chowdhury, Samit Karmakar

arXiv:cond-mat/0310556Physics Letters AOct 21, 200431 citations

U

increases, the sign of the current may oscillate depending on the total number of electrons

{N}_{e}

and the hopping

t

between the ring site and the side site. For small hopping

t

, the number of electrons ${N}_{e}^{\ensuremath{'}}$ in the ring sites plays an important role in determining the sign of the current. In contrast to the 1D Hubbard model, a weak or a moderate

U

can strongly enhance the persistent current while the hopping

t

always suppresses the current. The study on the transmittance of the ring with two connected leads indicates that in the large

U

and small

t

case, the transmittance varies with a period $1∕{N}_{e}^{\ensuremath{'}}$ of a flux quantum, demonstrating a spin-charge separation in this system.