You have to understand, most of these people are not ready to be unplugged. And many of them are so inured, so hopelessly dependent on the system, that they will fight to protect it.
You have to understand, most of these people are not ready to be unplugged. And many of them are so inured, so hopelessly dependent on the system, that they will fight to protect it.
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SpinChainFirstly, we make a lattice for a spin 1/2 chain, 20 sites. The default Hamiltonian will be the isotropic Heisenberg model spinchain-u1 -L 20 -S 0.5 -o lattice Now we make a random initial state with quantum number {$S^z=0$}, called 'psi' mp-random -l lattice -q 0 -o psi Run the DMRG program for the Heisenberg model, being the operator 'H' in the lattice. Here we are using m=50 states kept and the default is a single-site algorithm with a density matrix mixing term. mp-dmrg -w psi -H lattice:H -m 50 Repeat this command as needed until it is converged. The Hamiltonian operator can be more complicated. For example, for a bilinear-biquadratic {$S=1$} chain with {$S=1/2$} edge states at coupling {$\theta=0.3$}, and a reduced coupling strength 0.7J at the edges, use a lattice spinchain-u1 -L 20 -S 1 --SpinEdge=0.5 -o lattice with the Hamiltonian as lattice:"cos(0.3*pi)*(H1Bulk + 0.7*H1Edge) + sin(0.3*pi)*(H2Bulk + 0.7*H2Edge)" This same procedure can be done with {$SU(2)$} symmetry, by constructing the lattice with spinchain-su2 L 20 -S 0.5 -o lattice instead. |