Common energy scale for magnetism and superconductivity in cuprates
  Many compounds based on CuO_2 planes (cuprates) super-conduct below a critical temperature Tc. Some of them show a second phase where a spontaneous static magnetic field appears below a critical temperature Tg, which is lower then Tc. By comparing Tc and Tg in numerous superconducting families, each with its own maximum Tc, we find that the same energy scale determines both critical temperatures. This clearly indicates that superconductivity and magnetism are intimately related in the cuprates. 
Amit Keren, Amit Kanigel