Enhancement of the Bose glass phase in the presence of an artificial gauge field

Abstract

We examine the effects of an artificial gauge field and finite temperature in a two-dimensional disordered Bose-Hubbard model. The disorder considered is diagonal and quenched in nature. A signature of disorder in the Bose-Hubbard model is the Bose glass phase. Our work shows that the introduction of an artificial gauge field enhances the domain of the Bose glass phase in the phase diagram. Most importantly, the size of the domain can be tuned with the strength of the artificial gauge field. The introduction of the finite temperature effects is essential to relate theoretical results with the experimental realizations. For our studies we use the single site and cluster Gutzwiller mean-field theories. The results from the latter are more reliable as it better describes the correlation effects. Our results show that the Bose glass phase has a larger domain with the latter method.arXiv:1807.00269v2 [cond-mat.quant-gas]

Fine-grained domain counting and percolation analysis in 2D lattice systems with linked-lists

“…For the percolation analysis we take ∆ = 1.2U and µ = 0.2U , and scan the phases as a function of J/U . The phase diagram in the J/U − µ/U plane, as reported in [30], constitutes the BG and SF phases. The absence of the MI phase is due to the high disorder strength.…”

“…It shows an increase as the system enters the SF domain. Based on our previous work [30], we consider ρ s ≈ 10 −2 as a threshold for distinguishing between the BG and SF phase. The plot shows an increase in ρ s at J/U ≈ 0.017, and the threshold is crossed at J = 0.0174U .…”

“…The system is modeled with the disordered Bose-Hubbard model (DBHM). Earlier studies have identified the ground state phase diagram of the DBHM, and have shown the absence of a direct MI-to-SF transition [27][28][29][30][46][47][48]. The MI-SF transition is intervened by the BG phase, which is characterized by non-zero compressibility and zero superfluid stiffness.…”

“…We perform self-consistent calculation of φ p,q till the desired convergence is obtained. The details of using this method in our computations are given in our previous works [30,[38][39][40][41][42][43].…”

“…And, second, we study the critical properties in the Bose glass (BG) to SF transition of bosons in disordered optical lattices. The BG phase is insulating yet compressible and it is characterized by the SF puddles with an MI background [27][28][29][30]. Using our method we compute the geometrical properties of the SF clusters.…”