3D Chern-Simons Term breaks Meissner Effect
  It is well-known that (2+1)-dimensional Chern-Simons term may lead to topological Meissner effect. However, we show that 3-dimensional Chern-Simons term, which is different from (2+1)-dimensional Chern-Simons term, will instead destroy traditional Meissner effect. This means that the presence of a 3-dimensional Chern-Simons term naturally guarantees the validity of "pre-formed pairs" picture explaining high-T_c superconductivity, because such a term breaks Meissner effect induced by paired electrons. In particular, if 3-dimensional Chern-Simons gauge fields indeed emerge in the "pre-formed pairs" regime, our theory predicts that around the transition temperature T_c the Hall conductivity {\sigma} should exhibit a scaling law {\sigma}->(T-T_c )^(2/D) with D being the dimension of the superconducting material. 
Yong Tao
cond-mat.supr-con