We report time-resolved measurements of Landau-Zener tunneling of Bose-Einstein condensates in accelerated optical lattices, clearly resolving the steplike time dependence of the band populations. Using different experimental protocols we were able to measure the tunneling probability both in the adiabatic and in the diabatic bases of the system. We also experimentally determine the contribution of the momentum width of the Bose condensates to the temporal width of the tunneling steps and discuss the implications for measuring the jump time in the Landau-Zener problem.

A comprehensive study of the tunneling dynamics of a Bose-Einstein condensate in a tilted periodic potential is presented. We report numerical and experimental results on time-resolved measurements of the Landau-Zener tunneling of ultracold atoms introduced by the tilt,which experimentally is realized by accelerating the lattice. The use of different protocols enables us to access the tunneling probability, numerically as well as experimentally, in two different bases, namely, the adiabatic basis and the diabatic basis. The adiabatic basis corresponds to the eigenstates of the lattice, and the diabatic one to the free-particle momentum eigenstates. Our numerical and experimental results are compared with existing two-state Landau-Zener models

In this paper [1], the images of Figs. 4 and 5 should be exchanged. The captions and the corresponding citations in text remain correct as they are presented.

We numerically study the ground state properties of endohedrally confined hydrogen (H) or helium (He) atom by a molecule of C 60 . Our study is based on Diffusion Monte Carlo method. We calculate the effects of centered and small off-centered H-or He-atom on the ground state properties of the systems and describe the variation of ground state energies due to the C 60 parameters and the confined atomic nuclei positions. Finally, we calculate the electron distributions in x − z plane in a wide range of C 60 parameters.

Several ways are discussed how to control the Landau-Zener tunneling in the Wannier-Stark system. We focus on a realization of this system with interacting and noninteracting ultracold bosons. The tunneling from the ground band to the continuum is shown to depend crucially on the initial condition and system parameters and, more interestingly, on added timedependent disorder -noise -on the lattice beams.