Boson expansions for systems of interacting bosons

Stephan Langer, J. P. Ronzheimer, Michael Schreiber +6 more

J. Dobaczewski

Jie Ren, Yin‐Zhong Wu, Xuefen Xu

Using the adaptive time-dependent density matrix renormalization group method, we numerically investigate the expansion dynamics of bosons in a one-dimensional hard-core boson model with three-body interactions. It is found that the bosons expand ballistically with weak interaction, which are obtained by local density and the radius Rn. It is shown that the expansion velocity V, obtained from Rn = Vt, is dependent on the number of bosons. As a prominent result, the expansion velocity decreases with the enhancement of three-body interaction. We further study the dynamics of the system, which quenches from the ground state with two-thirds filling, the results indicate the expansion is also ballistic in the gapless phase regime. It could help us detect the phase transition in the system.

Heng Wu

By utilizing the 1/N expansion technique, the SU(3)-symmetry breaking caused by boson energies is discussed for the sdg Interacting Boson Model, and the analytical expressions of the intrinsic states are given under the approximation in the order of 1/N. It is also shown that the many body theories for a interacting boson system, such as Hartree-Bose method, Tamm- Dancoff approximation and Cranked Hartree approximation, are all special cases of the 1/N expansion technique.

Xiao-Gang Wen