Exact ground states with deconfined gapless excitations for the three-leg spin-1/2 tube

Miklós Lajkó, Philippe Sindzingre, Karlo Penc

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

We consider a spin-1/2 tube (a three-leg ladder with periodic boundary conditions) with a Hamiltonian given by two projection operators-one on the triangles and the other on the square plaquettes on the side of the tube-that can be written in terms of Heisenberg and four-spin ring exchange interactions. We identify 3 phases: (i) for strongly antiferromagnetic exchange on the triangles, an exact ground state with a gapped spectrum can be given as an alternation of spin and chirality singlet bonds between nearest triangles; (ii) for ferromagnetic exchange on the triangles, we recover the phase of the spin-3/2 Heisenberg chain; (iii) between these two phases, a gapless incommensurate phase exists. We construct an exact ground state with two deconfined domain walls and a gapless excitation spectrum at the quantum phase transition point between the incommensurate and dimerized phases.

Original languageEnglish
Article number017205
JournalPhysical review letters
Volume108
Issue number1
DOIs
Publication statusPublished - Jan 4 2012

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Exact ground states with deconfined gapless excitations for the three-leg spin-1/2 tube'. Together they form a unique fingerprint.

  • Cite this