Anyonic Liquids in Nearly Saturated Spin Chains

Most Heisenberg-like spin chains flow to a universal free-fermion fixed point near the magnetic-field induced saturation point. Here, we show that an exotic fixed point, characterized by two species of low-energy excitations with mutual anyonic statistics, may also emerge in such spin chains if the dispersion relation has two minima. By using bosonization, two-magnon exact calculations, and numerical densitymatrix-renormalization-group calculations, we demonstrate the existence of this anyonic-liquid fixed point in an XXZ spin chain with up to second-neighbor interactions. We also identify a range of microscopic parameters, which support this phase.