Advertisement

DLRO, ODLRO and superfluidity

  • Yosuke Nagaoka
Excitonic Condensation
Part of the Lecture Notes in Physics book series (LNP, volume 57)

Abstract

A necessary condition for superfluidity is discussed in connection with the classification of the long-range orders, DLRO and ODLRO, and it is concluded that it can take place only in systems with ODLRO. Based on this consideration, the possibility of superfluidity in a system of Frenkel excitons is examined. It is shown that it cannot occur in the excitonic phase, but that it can occur in the Bose-condensed phase of high-density excitons as a transient phenomenon.

Keywords

Gauge Symmetry Spin System Anisotropy Energy Spontaneous Magnetization Transient Phenomenon 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Reference

  1. 1).
    C. N. Yang: Rev. mod. Phys. 34 (1962), 694.Google Scholar
  2. 2).
    W. Kohn and D. Sherrington: Rev. mod. Phys. 42 (1970), 1.Google Scholar
  3. 3).
    T. Matsubara and H. Matsuda: Progr. theor. Phys. 16 (1956), 569.Google Scholar
  4. 4).
    We may generalize the definition of ODLRO to general conserved quantities. For instance, the order of the spin system with the Hamiltonian (4) is off-diagonal with respect to the z-component of spins which is the conserved quantity in this system. In this sense ODLRO is a necessary condition for superfluidity.Google Scholar
  5. 5).
    The possibility of superfluidity in this system was discussed by S. Nakajima; preprint. See also Nakajima's paper in this proceedings.Google Scholar
  6. 6).
    P. W. Anderson: Concepts in Solids (Benjamin, N.Y., 1964), p.132.Google Scholar
  7. 7).
    B. I. Halperin and T. M. Rice: Solid State Physics 21 (1968), 116.Google Scholar
  8. 8).
    E. Hanamura: J. Phys. Soc. Japan 29 (1970), 50;.ibid. 37 (1974), 1545.Google Scholar
  9. 8)a.
    E. Hanamura and H. Haug: Solid State Commun. 15 (1974), 1967.Google Scholar
  10. 8)b.
    See also Hanamura's and Haug's papers in this proceedings.Google Scholar

Copyright information

© Springer-Verlag 1976

Authors and Affiliations

  • Yosuke Nagaoka
    • 1
  1. 1.Department of PhysicsNagoya UniversityNagoyaJapan

Personalised recommendations