Quantum spin chains#
Exact diagonalization of spin-1/2 chains in their symmetry sectors, checked against the classic exact solutions: Bethe’s ansatz for the Heisenberg antiferromagnet, the free-fermion solution of the transverse-field Ising chain, and the Calabrese-Cardy logarithmic entanglement of a critical chain versus the area law of a gapped one.
Bethe’s ansatz for the Heisenberg antiferromagnetic chain
Bethe's ansatz for the Heisenberg antiferromagnetic chain
Calabrese-Cardy: logarithmic entanglement at criticality vs. the area law
Calabrese-Cardy: logarithmic entanglement at criticality vs. the area law
