Dipolar Bose Superstripes

We study the superfluid properties of a system of fully polarized dipolar bosons moving in the \(xy\) plane. We focus on the general case where the polarization field forms an arbitrary angle \(\alpha\) with respect to the \(z\) axis, while the system is still stable. We use the diffusion Monte Carlo and the path integral ground state methods to evaluate the one-body density matrix and the superfluid fractions in the region of the phase diagram where the system forms stripes. Despite its oscillatory behavior, the presence of a finite large-distance asymptotic value in the \(s\)-wave component of the one-body density matrix indicates the existence of a Bose condensate. The superfluid fraction along the stripes direction is always close to 1, while in the \(y\) direction decreases to a small value that is nevertheless different from zero. These two facts confirms that the stripe phase of the dipolar Bose gas in 2D is superfluid.