Hierarchy of exactly solvable spin- 1 2 chains with s o (N) 1 critical points
2014 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 89, no 1, 014409- p.Article in journal (Refereed) Published
We construct a hierarchy of exactly solvable spin-1/2 chains with so(N)1 critical points. Our construction is based on the framework of condensate-induced transitions between topological phases. We employ this framework to construct a Hamiltonian term that couples N transverse field Ising chains such that the resulting theory is critical and described by the so(N)1 conformal field theory. By employing spin duality transformations, we then cast these spin chains for arbitrary N into translationally invariant forms that all allow exact solution by the means of a Jordan-Wigner transformation. For odd N our models generalize the phase diagram of the transverse field Ising chain, the simplest model in our hierarchy. For even N the models can be viewed as longer ranger generalizations of the XY chain, the next model in the hierarchy. We also demonstrate that our method of constructing spin chains with given critical points goes beyond exactly solvable models. Applying the same strategy to the Blume-Capel model, a spin-1 generalization of the Ising chain in a generic magnetic field, we construct another critical spin-1 chain with the predicted conformal field theory (CFT) describing the criticality.
Place, publisher, year, edition, pages
2014. Vol. 89, no 1, 014409- p.
Nearest-Neighbor Interaction, Isotropic Heisenberg Chain, Quantum-Field Theory, 2 Dimensions, Ising Model, Antiferromagnetic Chain, Weak Ferromagnetism, Phase-Transitions, Transverse Field, Arbitrary Spins
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-143053DOI: 10.1103/PhysRevB.89.014409ISI: 000332206600001ScopusID: 2-s2.0-84892915374OAI: oai:DiVA.org:kth-143053DiVA: diva2:705465
FunderSwedish Research Council
QC 201403172014-03-172014-03-172014-03-27Bibliographically approved