Korrelationen und Suprafluidität in mesoskopischen Ensembles indirekter Exzitonen

Zusammenfassung der Projektergebnisse

The main focus of the present project was the theoretical study of correlation effects in a low temperature gas of indirect excitons and dipolar bosons. Recent experiments have confirmed existence of spontaneous onset of quantum coherence and superfluidity in these systems. In this respect, the indirect excitons offer a number of attractive features: a strong dipole-type interaction, the comparatively long radiative life time and the external controllability of the density and dipole moment. In our project, we have developed numerical and analytical methods to compute the effective interaction for indirect excitons and study their collective behavior from first principle simulations. We found the parameter-range where the quantum coherence effects are important and demonstrated the possibility of exciton crystallization, but experimental evidence is currently missing. As a result the full phase diagram for a quasitwo dimensional system of indirect excitons and dipolar bosons has been reconstructed.

Projektbezogene Publikationen (Auswahl)

• Controlling the radial distribution of superfluidity in mesoscopic Coulomb clusters. Phys. Rev. B 77, 214527 (2008)
  A. Filinov, J. Böning, M. Bonitz, and Yu.E. Lozovik
  
• Melting of Trapped Few-Particle Systems. Phys. Rev. Lett. 100, 113401 (2008)
  J. Böning, A. Filinov, P. Ludwig, H. Baumgartner, M. Bonitz, and Yu. E. Lozovik
  
• Path Integral Monte Carlo Simulations of Charged Particles in Traps. Chapter in: Springer Lecture Notes in Physics 739, 41, (2008): Computational Many-Particle Physics, H. Fehske, R. Schneider, A. Weiße (Eds.), Springer, Berlin 2008
  A. Filinov, J. Boening, and M. Bonitz
  
• Effective interaction potential and superfluid–solid transition of spatially indirect excitons. Journal of Physics A: Math. Theor. 42, 214016 (2009)
  A. Filinov, P. Ludwig, M. Bonitz, and Yu.E. Lozovik
  
• Electric field-induced exciton localization in quantum wells. phys. stat. sol. (c) 6, 551-555 (2009)
  K. Sperlich, P. Ludwig, A. Filinov, M. Bonitz, H. Stolz, D. Hommel, and A. Gust
  
• Berezinskii-Kosterlitz-Thouless Transition in Two-Dimensional Dipole Systems. Phys. Rev. Lett. 105, 070401 (2010)
  A. Filinov, N.V. Prokof’ev, and M. Bonitz
  
• Introduction to Quantum Plasmas. Chapter in: Springer Series: Atomic, Optical and Plasma Physics, M. Bonitz, Norman Horing, and Patrick Ludwig (Eds.), vol. 59, Springer, Berlin, 2010
  M. Bonitz, A. Filinov, J. Böning, and J.W. Dufty
  
• Crystallization of an exciton superfluid. Phys. Rev. B 84, 075130 (2011)
  J. Böning, A. Filinov and M. Bonitz