2 citations · 2 across the 2 of their papers we have counts for
6 papers
Defect and equivalence of unitary matrices. The Fourier case
Wojciech Tadej
Consider the real space D_U of directions moving into which from a unitary N x N matrix U we do not disturb its unitarity and the moduli of its entries in the first order. dim( D_U…
Defect of a Kronecker product of unitary matrices
Wojciech Tadej
The generalized defect D(U) of a unitary NxN matrix U with no zero entries is the dimension of the real space of directions, moving into which from U we do not disturb the moduli |…
Defect of a unitary matrix
Wojciech Tadej, Karol Zyczkowski
We analyze properties of a map B = f(U) sending a unitary matrix U of size N into a doubly stochastic matrix defined by B_{i,j} = |U_{i,j}|^2. For any U we define its DEFECT, deter…
Mubs and Hadamards of Order Six
Ingemar Bengtsson, Wojciech Bruzda, Asa Ericsson +3
We report on a search for mutually unbiased bases (MUBs) in 6 dimensions. We find only triplets of MUBs, and thus do not come close to the theoretical upper bound 7. However, we po…
A concise guide to complex Hadamard matrices
Wojciech Tadej, Karol Zyczkowski
Complex Hadamard matrices, consisting of unimodular entries with arbitrary phases, play an important role in the theory of quantum information. We review basic properties of comple…
Permutation Equivalence Classes of Kronecker Products of Unitary Fourier Matrices
Wojciech Tadej
Kronecker products of unitary Fourier matrices play important role in solving multilevel circulant systems by a multidimensional Fast Fourier Transform. They are also special cases…