Excitation spectrum of the (formula presented) quantum spin ladder with frustration: Elementary quasiparticles and many-particle bound states

Physical Review B - Condensed Matter and Materials Physics

Volumn 59, Issue 9, 1999, Pages 6266-6277

  Kotov, V N ^a   Sushkov, O P ^a   Eder, R ^b  

^a UNIVERSITY OF NEW SOUTH WALES   (Australia)

^b UNIVERSITY OF WÜRZBURG   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000014452     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.59.6266     Document Type: Article

References (29)

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24. Equation (30) can also be derived as a two-particle Schrödinger equation in momentum space (Formula presented) For the singlet bound state one has (Formula presented) where (Formula presented) are defined in the text before Eq. (28). For a triplet bound state with polarization (Formula presented) While this way of deriving the Bethe-Salpeter equation is quite simple and physically transparent, the approach presented in the text is more general and we give it preference since it is better suited for treating more complicated interaction terms [e.g., three-body interactions which appear in certain models with dimerization (Ref. 17)].
25. Strictly speaking Eq. (40) is valid for (Formula presented) However it works quite well even for (Formula presented) For example at the point (Formula presented) according to Eq. (40) (Formula presented) while the numerical result (Refs. 6 and 13) is (Formula presented)
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