Low-frequency dynamics of 1d quantum lattice gas: the case of local potential with double wells

: 235-241
Received: December 14, 2018
Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine
Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine
Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine

The quantum lattice gas model is used for investigation of low-frequency dynamics of the one-dimensional lattice (an analogue of the H-bonded atomic chain) with the two minima local anharmonic potential.  Short-range correlations and particle hopping within potential wells as well as between of them are taken into account. The dynamical dipole susceptibility that determines the dielectric response of the system, is calculated using the exact diagonalization procedure on clasters and the Green's function formalism. The density of vibrational states is found, its frequency dependence is analyzed. The splitting of the lowest branch in spectrum  in the region of transition to the ordered ground state (instead of the standard soft-mode behaviour) is revealed.

  1. Stasyuk I. V., Vorobyov O. Energy spectrum and phase diagrams of two-sublattice hard-core boson model. Condens. Matter Phys. 16, 23005 (2013).
  2. Menotti C., Trivedi N. Spectral weight redistribution in strongly correlated bosons in optical lattices. Phys. Rev. B. 77, 235120 (2008).
  3. Stasyuk I. V., Pavlenko N. I., Hilczer B. Proton ordering model of superionic phase transition in (NH4)3H(SeO4)2 crystal. Phase Transitions. 62, 135–156 (1997).
  4. Pavlenko N. I., Stasyuk I. V. The effect of proton interactions on the conductivity behaviour in systems with superionic phases. J. Chem. Phys. 114, 4607 (2001).
  5. Stasyuk I. V., Ivankiv O. L., Pavlenko N. I. Orientational-tunneling model of one-dimensional molecular systems with hydrogen bonds. J. Phys. Stud. 1 (3), 418–430 (1997).
  6. Stetsiv R. Ya., Stasyuk I. V., Vorobyov O. Energy spectrum and state diagrams of one-dimensional ionic conductor. Ukr. J. Phys. 59 (5), 515–522 (2014).
  7. Stasyuk I. V., Stetsiv R. Ya. Dynamic conductivity of one-dimensional ion conductors. Impedance, Nyquist diagrams. Condens. Matter Phys. 19, 43704 (2016).
  8. Mahan G. D. Lattice gas theory of ionic conductivity. Phys. Rev. B. 14, 780 (1976).
  9. Kobayashi K. Dynamical theory of the phase transition in KH2PO4-type ferroelectric crystals. J. Phys. Soc. Japan. 24, 497–508 (1968).
  10. De Gennes P. G. Collective motion of hydrogen bond. Solid State Commun. 1, 132-137 (1963).
  11. Stasyuk I. V., Stetsiv R. Ya., Sizonenko Yu. V. Dynamics of charge transfer along hydrogen bond. Condens. Matter Phys. 5 (4), 685–706 (2002).
  12. Stasyuk I. V., Levitskii R. R., Moina A. P. External pressure influence on ferroelectrics and antiferroelectrics of KH2PO4 family: A unified model. Phys. Rev. B. 59, 8530–8540 (1999).
  13. Blinc R., Žekš B. Dynamics of order-disorder-type ferroelectrics and antiferroelectrics. Adv. Phys. 21, 693–757 (1972).
  14. Blinc R. The soft mode in H-bonded ferroelectrics revisited. Croat. Chem. Acta. 55 (1–2), 7–13 (1982).
  15. Münch W., Kreuer K. D., Traub U.,Maier J. A molecular dynamics study of the high proton conductivity phase of CsHSO4. Solid State Ionics. 77, 10–14 (1995).
  16. Hassan R., Campbell E. S. The energy and structure of Bjerrum defects in the ice 1h determined with an additive and a nonadditive potential. J. Chem. Phys. 97 (6), 4362–4335 (1992).
  17. Stöferle T., Moritz H., Schori C., Köhl M., Esslinger T. Transition from a strongly interacting 1D superfluid to a Mott insulator. Phys. Rev. Lett. 92, 130403 (2004).
  18. Incci A., Cazalilla M. A., Ho A. F., Gianmarchi T. Energy absorption of a Bose gas in a periodically modulated optical lattice. Phys. Rev. A. 73, 041608(R) (2006).
Math. Model. Comput. Vol. 5, No. 2, pp. 235-241 (2018)