We present a way to construct indecomposable entanglement witnesses from any permutations π with π2 ≠ id for any finite dimensional bipartite systems. Some new bounded entangled states are also fou...
Let n≥2 and Φn,t,π:Mn(C)→Mn(C) be a linear map defined by Φn,t,π(A)=(n−t)∑i=1nEiiAEii+t∑i=1nEi,π(i)AEi,π(i)†−A, where 0≤t≤n, Eijs are the matrix units and π is a non-identity permutation of (1,2,⋯,n). Denote by {Fs:s=1,2…,k} the set of all minimal cycles of π and l(π)=max{#Fs:s=1,2,…,k} the length of π. It is shown that the Hermitian matrix Wn,t,π induced by Φn,t,π is an indecomposable entanglement witness if and only if π2=id (the identity permutation) and $0