Convolution algebra of superoperators and nonseparability witnesses for quantum operations
arXiv:2108.08776 · doi:10.1088/1751-8121/ac7485
Abstract
We define a product between quantum superoperators which is preserved under the Choi-Jamiołkowski-Kraus-Sudarshan channel-state isomorphism. We then identify the product as the convolution on the space of superoperators, with respect to which the channel-state duality is also an algebra isomorphism. We find that any witness operator for detecting nonseparability of quantum operations on separated parties can be written entirely within the space of superoperators with the help of the convolution product.
9 pages