Field-induced spin-solid phases in the spin liquids Tb$_{2}$Ti$_{2}$O$_{7}$ and Nd$_{3}$Ga$_{5}$SiO$_{14}$

Here we report thermodynamic and magnetization measurements at zero and high fields in the pyrochlore Tb$_{2}$Ti$_{2}$O$_{7}$ and in the Kagome lattice Nd$_{3}$Ga$_{5}$SiO$_{14}$. In both compounds, previous neutron scattering studies did not reveal any form of magnetic ordering down to the lowest temperatures and have proposed these materials to display a spin-liquid ground state [1]. Here we show that heat capacity normalized by temperature down to $\sim $ 350 mK confirms the absence of ordering. Furthermore, magnetization as a function of field at the lowest temperatures reveal the existence of an intermediary phase protruded between the zero field spin-liquid and the high-field spin-polarized state. In the case Nd$_{3}$Ga$_{5}$SiO$_{14 }$it leads to a 1/2 magnetization plateau for fields along the inter-planar direction, similar to the one recently reported in the pyrochlore compound CdCr$_{2}$O$_{4}$ [2]. But for fields along the planes it displays a 1/3 plateau followed by a metamagnetic transition towards a value closer to 4/5. [1] J. S. Gardner et al. Phys. Rev. Lett. 82, 1012 (1999)~; J. Robert et al., ibid 96\textbf{, }197205 (2006) [2] H. Ueda, Phys. Rev. Lett. 94, 047202 (2005).