Cliò Efthimia Agrapidis, StefanLudwig Drechsler, Jeroen van den Brink, Satoshi Nishimoto
SciPost Phys. 6, 019 (2019) ·
published 6 February 2019

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Frustrated onedimensional (1D) magnets are known as ideal playgrounds for
new exotic quantum phenomena to emerge. We consider an elementary frustrated 1D
system: the spin$\frac{1}{2}$ ferromagnetic ($J_1$) Heisenberg chain with
nextnearestneighbor antiferromagnetic ($J_2$) interactions. On the basis of
densitymatrix renormalization group calculations we show the existence of a
finite spin gap at $J_2/J_1>1/4$ and we find the ground state in this region
to be a valence bond solid (VBS) with spinsinglet dimerization between
thirdneighbor sites. The VBS is the consequence of spontaneous symmetry
breaking through order by disorder. Quite interestingly, this VBS state has a
AffleckKennedyLiebTasakitype topological order. This is the first example
of a frustrated spin chain in which quantum fluctuations induce gapped
topological order.
Ms Agrapidis: "We thank the referee for his/h..."
in Report on Coexistence of valencebond formation and topological order in the Frustrated Ferromagnetic $J_1$$J_2$ Chain