Ground-State Phase Diagram of Frustrated Anisotropic Quantum Spin Chains
  Recent studies on the frustrated quantum spin chains with easy-plane anisotropy are reviewed. We are particularly interested in novel "chiral" phases characterized by the spontaneous breaking of the parity symmetry. The ground-state phase diagrams of the chains are discussed. 
T.Hikihara, M.Kaburagi, H.Kawamura