Novel Phenomena in Charged Bose Liquid

We investigate charged Bose liquid immersed in uniform background charge at zero temperature. Novel phenomena, such as oscillatory shielding of external localized electric charge, rotons and charge density waves (charge stripes in two dimensions), occur in any dimensions. Oscillatory shielding is caused by mixing between scalar boson exchange and Coulomb interactions, which mediate opposite forces. On the other hand, rotons and charge density waves are due to attractive local self-interaction of bosons. Rotons can be regarded as a finite size charge density wave packet without any back flow. We also comment on charge stripes observed recently in cuprates and nickelates.