caa a22 4500 445366478 CHVBK 20180317142932.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s10909-011-0395-4 doi (NATIONALLICENCE)springer-10.1007/s10909-011-0395-4 Improved Variational Approach to the Two-Site Bose-Hubbard Model [Elektronische Daten] [M. Melé-Messeguer, B. Juliá-Díaz, A. Polls] An improved variational ansatz is proposed to capture the most striking properties of the ground state of a slightly biased attractive two-site Bose-Hubbard Hamiltonian. Our ansatz, albeit its simplicity, is found to capture well the exact properties of the ground state for a wide variety of model parameters, in particular the fragmentation occurring before the formation of cat-like states and also the formation of strongly correlated cat-like states. Springer Science+Business Media, LLC, 2011 Tunneling nationallicence Josephson effect nationallicence Bose-Einstein condensates nationallicence Melé-Messeguer M. Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, 08028, Barcelona, Spain aut Juliá-Díaz B. Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, 08028, Barcelona, Spain aut Polls A. Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, 08028, Barcelona, Spain aut Journal of Low Temperature Physics Springer US; http://www.springer-ny.com 165/5-6(2011-12-01), 180-194 0022-2291 165:5-6<180 2011 165 10909 https://doi.org/10.1007/s10909-011-0395-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10909-011-0395-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Melé-Messeguer M. Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, 08028, Barcelona, Spain aut NATIONALLICENCE 700 1- Juliá-Díaz B. Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, 08028, Barcelona, Spain aut NATIONALLICENCE 700 1- Polls A. Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, 08028, Barcelona, Spain aut NATIONALLICENCE 773 0- Journal of Low Temperature Physics Springer US; http://www.springer-ny.com 165/5-6(2011-12-01), 180-194 0022-2291 165:5-6<180 2011 165 10909 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer