Quadrature Squeezing in Extended Two-Site Bose–Hubbard Model with Pair Tunneling

We analytically and numerically investigate quadrature squeezing in an extended two-site Bose–Hubbard model with pair tunneling by using the rotating-wave approximation. It is shown that single particle tunneling and the density-dependent tunneling have no influence on quadrature squeezing; the onsite interaction and the inter-well particle interactions effect the regime of squeezing under some conditions.