Lengthy-range ferroelectric crystalline order normally fades away because the spatial dimension decreases, therefore there are few two-dimensional (2D) ferroelectrics and much fewer one-dimensional (1D) ferroelectrics. As a result of depolarization subject, low-dimensional ferroelectrics hardly ever possess the polarization alongside the route of lowered dimensionality. Right here, utilizing first-principles density practical concept, we discover the structural evolution of nanoribbons of various widths constructed by chopping the 2D sheet of ferroelectric α-III2VI3 (III=Al, Ga, In; VI=S, Se, Te). We uncover a one-dimensional ferroelectric nanothread (1DFENT) of ultrasmall diameter with each axial and radial polarization, probably enabling ultra-dense knowledge storage with a 1D area of simply three unit cells being the practical unit. The polarization in 1DFENT of Ga2Se3 displays an uncommon piezoelectric response: a stretching stress alongside the axial route will enhance each axial and radial polarization, known as auxetic piezoelectric impact. Using the intrinsically flat digital bands, we show the coexistence of ferroelectricity and ferromagnetism in 1DFENT and a counterintuitive charge-doping-induced metal-to-insulator transition. The 1DFENT with each axial and radial polarization gives a counterexample to the Mermin–Wagner theorem in 1D and suggests a brand new platform for the design of ultrahigh-density reminiscence and the exploration of unique states of matter.
