@article{halu_phase_2012,
Author = {Halu, Arda and Ferretti, Luca and Vezzani, Alessandro
and Bianconi, Ginestra},
Title = {Phase diagram of the {Bose}-{Hubbard} {Model} on
{Complex} {Networks}},
Journal = {EPL (Europhysics Letters)},
Volume = {99},
Number = {1},
Pages = {18001},
abstract = {Critical phenomena can show unusual phase diagrams
when defined in complex network topologies. The case of
classical phase transitions such as the classical Ising
model and the percolation transition has been studied
extensively in the last decade. Here we show that the
phase diagram of the Bose-Hubbard model, an exclusively
quantum mechanical phase transition, also changes
significantly when defined on random scale-free
networks. We present a mean-field calculation of the
model in annealed networks and we show that when the
second moment of the average degree diverges, the
Mott-insulator phase disappears in the thermodynamic
limit. Moreover we study the model on quenched networks
and we show that the Mott-insulator phase disappears in
the thermodynamic limit as long as the maximal
eigenvalue of the adjacency matrix diverges. Finally we
study the phase diagram of the model on Apollonian
scale-free networks that can be embedded in 2
dimensions showing the extension of the results also to
this case.},
doi = {10.1209/0295-5075/99/18001},
year = 2012
}