Stuttgart 2012 – wissenschaftliches Programm
Q 35.24: Poster
Mittwoch, 14. März 2012, 16:30–19:00, Poster.I+II
Trion and Dimer Formation of three Fermions in an optical lattice — •Jan Pohlmann1, Antonio Privitera1,2, Irakli Titvinidze1,3, and Walter Hofstetter1 — 1Institut für Theoretische Physik, Johann Wolfgang Goethe-Universität, 60438 Frankfurt am Main, Germany — 2Democritos National Simulation Center, Consiglio Nazionale delle Ricerche Istituto Officina dei Materiali (IOM) and Scuola Internazionale Superiore di Studi Avanzati (SISSA), 34136 Trieste, Italy — 3Institut für Theoretische Physik, Universität Hamburg, 20355 Hamburg, Germany
We study the problem of three fermions with different hyperfine states in a lattice for D=1,2, considering the case of SU(3) attractive interactions and also including a three-body constraint, which mimics the effect of strong three-body losses. We combine an exact diagonalization approach with the Lanczos method, and evaluate both eigenvalues and eigenstates of the problem.
In D=1, we observe that the ground state is always a three-body bound state (trion), while in D=2, due to the stronger influence of finite-size effects, we are not able to identify the existence of a finite threshold for trion formation. Our data are however compatible with a threshold value which vanishes logarithmically with the system size. Moreover we are able to identify the presence of a fine structure inside the spectrum, which we associate with off-site trionic states. Finally, the inclusion of a three-body constraint due to losses stabilizes these off-site trions in the ground state, at least in strong-coupling.