Quantum order-from-disorder in frustrated spin nanotubes

We investigate purely quantum order-from-disorder in a frustrated spin nanotube, described by a J₁-J₂ Heisenberg model wrapped around a cylinder. Using Schwinger boson theory and Density Matrix Renormalization Group (DMRG), we compute the ground-state phase diagram, revealing a Z₂ phase in which the collinear spin stripes form either a right or left handed helix around the nanotube. We derive an analytic estimate for the critical η_c=J₁/2J₂ where the Z₂ phase transition occurs which is in agreement with the DMRG results.