PT Unknown AU Böning, J TI Superfluidity and Correlations in Systems of Indirect Excitons PY 2011 PU Christian-Albrechts-Universität zu Kiel WP https://macau.uni-kiel.de/receive/diss_mods_00006686 LA en DE superfluidity; crystallization; numerical simulation; Monte-Carlo method; spatially indirect excitons; 2D system; phase transitions; Suprafluidität; Kristallisation; numerische Simulation; Monte-Carlo Methode; indirekte Exzitonen; Phasenübergang AB Semiconductors feature two types of charge carriers, electrons and holes. These may bind in a meta-stable, hydrogen-like boson called exciton. A large number of excitons may populate the same state below a critical temperature (Bose-Einstein condensate). This work studies indirect excitons created from spatially separated electrons and holes. The model uses an effective interaction which incorporates effects encountered in realistic experimental setups. Predictions for the many-body system are based on first principle Path Integral Monte-Carlo simulations. The phase diagram exhibits two quantum phase transitions from solid to superfluid confining the solid phase to a finite density interval. The low-density boundary agrees to the behavior of polarized dipoles while the other is usually encountered in Coulomb systems. The transitions coincide at a critical dipole moment below which the solid cannot exist. Both superfluid and solid exist only at low temperatures. PI Kiel ER