Relaxation of frustration and gap enhancement by the lattice distortion in the Δ chain

Tota Nakamura, Satoshi Takada

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10 Citations (Scopus)


We consider the instability of the ground state of the Δ chain against a lattice distortion increasing the bond strength (λ) in each triangle. It relaxes the frustration and causes a remarkable gap enhancement; only a 6% increase of λ doubles the gap compared to the fully-frustrated case (λ = 1). The lowest excitation is revealed to be a kink-antikink bound state whose correlation length decreases drastically with λ increase. The enhancement follows a power law, ΔEgap ∼ (λ - 1) + 1.44(λ - 1)2/3, which can be obtained from the exact result of the continuum model.

Original languageEnglish
Pages (from-to)315-320
Number of pages6
JournalPhysics Letters, Section A: General, Atomic and Solid State Physics
Issue number4-6
Publication statusPublished - 1997 Feb 3



  • Frustrated quantum spin chain
  • Spin gap

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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