Witness for edge states and its characteristics

Edge states lying at the edge of PPT entangled states have a very intriguing existence and their detection is equally interesting. We present here a new witness for detection of edge states. We then compare between our proposed witness operator and the witness operator proposed in [Physical Review A, 62, 052310 (2000)] in terms of the efficiency in the detection of PPT entangled states. In this regard we show that this operator is finer than the Lewenstein et.al. operator in some restriction. We also discuss about its experimental realization via Gell-Mann matrices.