Collective spin density excitation of fractional quantum Hall states in dilute ultra-cold Bose atoms

Spin-flip excitation and negative energy dispersion in rotating Bose atoms

“…The range of interaction does not affect the nature of spectra. The intriguing point is that we found anomalous negative dispersion in the excited spectra, while a positive dispersion has only been recorded in the literature for Jain's first series [13]. We observed that SFE exhibits negative curvature and roton minima at lower momenta in the higher Jain series, whereas at higher momenta it enables spin-wave excitation similar to conventional ferromagnets.…”

“…Although all the FQH states having filling fractions less than one are basically 2D ferromagnets but in literature fundamentally different nature of the spin-wave excitation spectra is reported by Wurstbauer et al [12] for electronic FQH states of Jain's series. Also, the spin-flip excitation spectra for Jain's first series in the bosonic FQH system is studied by Indra and Majumder [13], which obeys the spin-wave positive dispersion. Bose-Einstein condensation (BEC) is first achieved by Cornell and Wieman using rubidium (Rb) atoms and later by Ketterle using sodium (Na) atoms [14].…”

Double roton-minima in bosonic fractional quantum Hall states

“…al. [27] demonstrated the variation of ground state energies for the three filling fractions using PT-interaction potential. Here we calculated the excitation spectra (∆) for ν = 1/4, 1/6 for both long-range and short-range interaction potential considering variation of range of interaction.…”

“…As we raise the μ-value, then the essence of PT-interaction goes well with δ-function. But for smaller values of μ the nature of PT potential differs from the contact interaction, as the range of interaction increases with decrease of μ [27,28]. That's why we have considered μ-values between a specific range in our calculation.…”