81 citations · 215 across the 13 of their papers we have counts for
13 papers
On unital qubit channels
Chi-Kwong Li, Man-Duen Choi
A canonical form for unital qubit channels under local unitary transforms is obtained. In particular, it is shown that the eigenvalues of the Choi matrix of a unital quantum channe…
A 3x3 dilation counterexample
Man Duen Choi, Kenneth R. Davidson
We define four 3x3 commuting contractions which do not dilate to commuting isometries. However they do satisfy the scalar von Neumann inequality. These matrices are all nilpotent o…
Symmetry in the Cuntz Algebra on two generators
Man-Duen Choi, Frederic Latremoliere
We investigate the structure of the automorphism of which exchanges the two canonical isometries. Our main observation is that the fixed point C*-subalgebra for t…
Product numerical range in a space with tensor product structure
Zbigniew Puchała, Piotr Gawron, Jarosław Adam Miszczak +3
We study operators acting on a tensor product Hilbert space and investigate their product numerical range, product numerical radius and separable numerical range. Concrete bounds f…
The multiplicative domain in quantum error correction
Man-Duen Choi, Nathaniel Johnston, David W. Kribs
We show that the multiplicative domain of a completely positive map yields a new class of quantum error correcting codes. In the case of a unital quantum channel, these are precise…
Corners of normal matrices
Rajendra Bhatia, Man-Duen Choi
We study various conditions on matrices and under which they can be the off-diagonal blocks of a partitioned normal matrix.