Neutron elastic scattering experiments have been performed on the spin gap system TlCuCl3 in magnetic fields parallel to the b-axis. The magnetic Bragg peaks which indicate the field-induced N\'{e}el ordering were observed for magnetic field higher than the gap field Hg≈5.5 T at Q=(h,0,l) with odd l in the a∗−c∗ plane. The spin structure in the ordered phase was determined. The temperature and field dependence of the Bragg peak intensities and the phase boundary obtained were discussed in connection with a recent theory which describes the field-induced N\'{e}el ordering as a Bose-Einstein condensation of magnons.
@article{arxiv.cond-mat/0101276,
title = {Observation of Field-Induced Transverse N\'{e}el Ordering in the Spin Gap System TlCuCl$_3$},
author = {H. Tanaka and A. Oosawa and T. Kato and H. Uekusa and Y. Ohashi and K. Kakurai and A. Hoser},
journal= {arXiv preprint arXiv:cond-mat/0101276},
year = {2009}
}