The phase diagram of the two-leg Kondo ladder is investigated using computational techniques. Ferromagnetism is present, but only at small conduction electron densities and robust Kondo coupling $J$ . For densities $n\ensuremath{\gtrsim}0.4$ and any Kondo coupling, a paramagnetic phase is found. We also observed spin dimerization at densities $n=1∕4$ and $n=1∕2$ . The spin-structure factor at small $J$ peaks at $\stackrel{P\vec}{q}=(2n,0)\ensuremath{\pi}$ for $n\ensuremath{\lesssim}0.5$, and at $\stackrel{P\vec}{q}=(n,1)\ensuremath{\pi}$ for $n\ensuremath{\gtrsim}0.5$. The charge structure factor suggests that electrons behave as free particles with spin $\ensuremath{-}1∕2$ (spin-0) for small (large) $J$ .The phase diagram of the two-leg Kondo ladder is investigated using computational techniques. Ferromagnetism is present, but only at small conduction electron densities and robust Kondo coupling $J$. For densities $n\ensuremath{\gtrsim}0.4$ and any Kondo coupling, a paramagnetic phase is found. We also observed spin dimerization at densities $n=1∕4$ and $n=1∕2$. The spin-structure factor at small $J$ peaks at $\stackrel{P\vec}{q}=(2n,0)\ensuremath{\pi}$ for $n\ensuremath{\lesssim}0.5$, and at $\stackrel{P\vec}{q}=(n,1)\ensuremath{\pi}$ for $n\ensuremath{\gtrsim}0.5$. The charge structure factor suggests that electrons behave as free particles with spin $\ensuremath{-}1∕2$ (spin-0) for small (large) $J$.

arXiv:cond-mat/0405380Physical Review BNov 23, 20046 citations

Quantum phases of a strongly disordered two-legged Josephson ladder

Anonymous, Efrat Shimshoni

Physical review. B./Physical review. BAug 17, 20260 citations

Frustrated spin -1/2 two-leg and three-leg antiferromagnetic Heisenberg ladders

Ningsheng Zhu

The goal of this project is to study the ground-state properties of frustrated spin-1/2 two- and three-leg Heisenberg ladders, and to investigate possible effects of diagonal couplings on spin gaps. The ground-state and the first-excited-state energies of these two systems are calculated systematically by using the density matrix renormalization group method. The ground state phase diagrams for these two systems are obtained. For the frustrated two-leg ladder, we found that the spin gap is insensitive to the change of the FM diagonal coupling constant. This is in agreement with experimental suggestions. For the frustrated three-leg ladder, we conclusively proved that introducing AF diagonal couplings can not change the gapless property of the ground state.The goal of this project is to study the ground-state properties of frustrated spin-1/2 two- and three-leg Heisenberg ladders, and to investigate possible effects of diagonal couplings on spin gaps. The ground-state and the first-excited-state energies of these two systems are calculated systematically by using the density matrix renormalization group method. The ground state phase diagrams for these two systems are obtained. For the frustrated two-leg ladder, we found that the spin gap is insensitive to the change of the FM diagonal coupling constant. This is in agreement with experimental suggestions. For the frustrated three-leg ladder, we conclusively proved that introducing AF diagonal couplings can not change the gapless property of the ground state.

May 29, 20190 citations

The phase diagram of the two-leg Kondo ladder is investigated using computational techniques. Ferromagnetism is present, but only at small conduction electron densities and robust Kondo coupling

J

. For densities $n\ensuremath{\gtrsim}0.4$ and any Kondo coupling, a paramagnetic phase is found. We also observed spin dimerization at densities

n=1∕4

and

n=1∕2

. The spin-structure factor at small

J

peaks at $\stackrel{P\vec}{q}=(2n,0)\ensuremath{\pi}$ for $n\ensuremath{\lesssim}0.5$, and at $\stackrel{P\vec}{q}=(n,1)\ensuremath{\pi}$ for $n\ensuremath{\gtrsim}0.5$. The charge structure factor suggests that electrons behave as free particles with spin $\ensuremath{-}1∕2$ (spin-0) for small (large)

J