1,721,029 research outputs found
Quantum computers,Computer quantistici
No full textA cosa serve un computer quantistico e come si puo' realizzare fisicament
Coherent Control of Dressed Matter Waves
No full textWe demonstrate experimentally that matter waves can be coherently and adiabatically loaded and controlled in one-, two-, and three-dimensional strongly driven optical lattices. This coherent control is then used in order to reversibly induce the superfluid-Mott insulator phase transition by changing the strength of the driving. Our findings pave the way for studies of driven quantum systems and new methods for controlling matter waves
Hitting Bose-Einstein condensates with a comb: evolution of interference patterns inside a magnetic trap
No full textWe study the evolution inside a harmonic trap of Bose-Einstein condensates released from the periodic potential of an optical lattice. After a time-of-flight, harmonic motion of the interference peaks is observed as well as a breathing motion in the direction perpendicular to the optical lattice. We interpret these results in terms of a simple physical model and discuss the possibility of more detailed studies of such a system
Bose-Einstein condensates in 1D optical lattices: nonlinearity and Wannier-Stark spectra
No full textQuantum control in strongly driven optical lattices
No full textMatter waves can be coherently and adiabatically loaded and controlled in
strongly driven optical lattices. This coherent control is used in order to
modify the modulus and the sign of the tunneling matrix element in the
tunneling Hamiltonian. Our findings pave the way for studies of driven quantum
systems and new methods for engineering Hamiltonians that are impossible to
realize with static techniques
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Expansion of matter waves in static and driven periodic potentials
Full text linkWe study the non-equilibrium dynamics of cold atoms held in an optical
lattice potential. The expansion of an initially confined atom cloud occurs in
two phases: an initial quadratic expansion followed by a ballistic behaviour at
long times. Accounting for this gives a good description of recent experimental
results, and provides a robust method to extract the effective intersite
tunneling from time-of-flight measurements
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