Coherence properties of two trapped particles
Department of Physics, University of Strathclyde, Glasgow G4 0NG, Scotland, UK
2 Physics Department, National University of Ireland, University College, Cork, Ireland, UK
Published online: 4 February 2003
We analyse the coherence properties of two particles trapped in a one-dimensional harmonic potential. This simple model allows us to derive analytic expressions for the first and second order coherence functions. We investigate their properties depending on the particle nature and the temperature of the quantum gas. We find that at zero temperature non-interacting bosons and fermions show very different correlations, while they coincide for higher temperatures. We observe atom bunching for bosons and atom anti-bunching for fermions. When the effect of s-wave scattering between bosons is taken into account, we find that the range of coherence is enhanced or reduced for repulsive or attractive potentials, respectively. Strongly repelling bosons become in some way more “fermion-like" and show anti-bunching. Their first order coherence function, however, differs from that for fermions.
PACS: 05.30.-d – Quantum statistical mechanics / 03.75.-b – Matter waves / 42.50.Lc – Quantum fluctuations, quantum noise, and quantum jumps
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003