Free field realization of the exceptional current superalgebra   $\hat{D(2,1;\a)}_k$
  The free-field representations of the $D(2,1;\a)$ current superalgebra and the corresponding energy-momentum tensor are constructed. The related screening currents of the first kind are also presented. 
Xi Chen, Wen-Li Yang, Xiang-Mao Ding, Jun Feng, San-Min Ke, Ke Wu and   Yao-Zhong Zhang
hep-th math-ph math.MP