English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the excitation spectrum of the two-chain S=1/2 Heisenberg spinladder with additional inter-chain second-neighbor frustrating interactions.The one and two-particle excitations are analyzed by using a mapping of themodel onto a Bose gas of hard-core triplets. We find that low-lying singlet andtriplet two-particle bound states are present and their binding energyincreases with increasing frustration. In addition, many-particle bound statesare found by a combination of variational and exact diagonalization techniques.We prove that the larger the number of bound quasiparticles the larger thebinding energy. Thus the excitation spectrum has a complex structure andconsists of elementary triplets and collective many-particle singlet andtriplet excitations which generally mix with the elementary ones.  The model exhibits a quantum phase transition from an antiferromagneticladder phase (small frustration) into Haldane phase (effectively ferromagneticladder for large frustration). We argue that near the transition point thespectrum in both triplet and singlet channels becomes gapless. The excitationwave function is dominated by large-size bound states which leads to thevanishing of the quasiparticle residue.Comment: RevTeX, 23 pages, 12 figure

physical review. b, condensed matter

Excitation spectrum of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>S</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn><mml:mn /></mml:math>quantum spin ladder with frustration: Elementary quasiparticles and many-particle bound states

Excitation spectrum of theS=1/2quantum spin ladder with frustration: Elementary quasiparticles and many-particle bound states