Number Density Distributions of Ultracold Bosons in 3D Optical Lattices

Corinna Kollath, Ulrich Schollwöck

K. Sengupta

Gaétan Hercé, Cécile Carcy, Antoine Ténart +4 more

The authors experimentally determine the superfluid-to-Mott-insulator phase transition points for bosons in a three-dimensional optical lattice through the measurement of the 3D momentum distribution. The results are benchmarked by quantum Monte Carlo simulations of a finite-temperature Bose-Hubbard model and demonstrate the powerful ability of the ultracold atomic systems in quantum simulations of critical phenomena.

Ippei Danshita, JAMES E. JUN. WILLIAMS, Carlos A. R. Sá de Melo +1 more

Yunzhi Tan, Qiang Zhu, Bing Wang +3 more

Density-density correlation analysis is a convenient diagnostic tool to reveal the hidden order in the strongly correlated phases of ultracold atoms. We report on a study of the density-density correlations of ultracold bosonic atoms which were initially prepared in a Mott insulator (MI) state in one-dimensional optical lattices. For the atomic gases released from the deep optical lattice, we extracted the normalized density-density correlation function from the atomic density distributions of freely expanded atomic clouds. Periodic bunching peaks were observed in the density-density correlation spectra, as in the case of higher-dimensional lattices. Treating the bosonic gas within each lattice well as a subcondensate without quantum tunneling, we simulated the post-expansion density distribution along the direction of the 1D lattice, and the calculated density-density correlation spectra agreed with our experimental observations.

Manjari Gupta