Eur. Phys. J. D 11, 335-339 (2000)
https://doi.org/10.1007/PL00011155

Kinetic energy of a trapped Fermi gas interacting with a Bose-Einstein condensate

¹ Istituto Nazionale per la Fisica della Materia and Dipartimento di Fisica, Università di Trento, Via Sommarive 14, 38050 Povo, Italy
² Istituto Nazionale per la Fisica della Materia and Classe di Scienze, Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy

Received: 13 September 1999
Revised: 22 February 2000
Published online: 15 September 2000

Abstract

We study a confined mixture of bosons and fermions in the regime of quantal degeneracy, with particular attention to the effects of the interactions on the kinetic energy of the fermionic component. We are able to explore a wide region of system parameters by identifying two scaling variables which completely determine its state at low temperature. These are the ratio of the boson-fermion and boson-boson interaction strengths and the ratio of the radii of the two clouds. We find that the effect of the interactions can be sizeable for reasonable choices of the parameters and that its experimental study can be used to infer the sign of the boson-fermion scattering length. The interplay between interactions and thermal effects in the fermionic kinetic energy is also discussed.