Volume 84, Number 3, November 2008
Article Number 37010
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 29 October 2008
EPL, 84 (2008) 37010
DOI: 10.1209/0295-5075/84/37010

Ground-state properties of fermionic mixtures with mass imbalance in optical lattices

P. Farkašovský

Institute of Experimental Physics, Slovak Academy of Sciences - Watsonová 47, 040 01 Košice, Slovakia, EU

received 19 June 2008; accepted in final form 1 October 2008; published November 2008
published online 29 October 2008

Ground-state properties of fermionic mixtures confined in a one-dimensional optical lattice are studied numerically within the spinless Falicov-Kimball model with a harmonic trap. A number of remarkable results are found. i) At low particle filling the system exhibits phase separation with heavy atoms in the center of the trap and light atoms in the surrounding regions. ii) Insulating phases always coexist with metallic phases. iii) Atomic-density waves are observed in the insulating regions for all particle fillings near the half-filled lattice case. iv) The variance of the local density exhibits universal behavior (independent of the particle filling, the Coulomb interaction and the strength of a confining potential) over the whole region of the local density values.

71.10.-w - Theories and models of many-electron systems.
71.30.+h - Metal-insulator transitions and other electronic transitions.
05.30.Fk - Fermion systems and electron gas.

© EPLA 2008