Observation of Bose–Einstein Condensation of Triplons in Quasi 1D Spin-Gap System Pb₂V₃O₉

Abstract

We observed a field-induced magnetic ordering in the quasi one-dimensional antiferromagnetic alternating chain system Pb 2 V 3 O 9 for the first time. The characteristic temperature dependence of the magnetic susceptibility below T N and the power law behavior of phase boundary between paramagnetic and ordered phases in the Pb 2 V 3 O 9 system can be comprehended in terms of Bose–Einstein condensation of triplons, as in the case of TlCuCl 3 [Phys. Rev. Lett. 84 (2000) 5868]. Our results indicate that BEC of triplons can be observed in the present strongly-coupled-dimer system, while TlCuCl 3 is a weak inter dimer coupling system.