4 papers
Quantum magic squares: dilations and their limitations
Gemma De las Cuevas, Tom Drescher, Tim Netzer
Quantum permutation matrices and quantum magic squares are generalizations of permutation matrices and magic squares, where the entries are no longer numbers but elements from arbi…
Generalised ansatz for continuous Matrix Product States
Maria Balanzó-Juandó, Gemma De las Cuevas
Recently it was shown that continuous Matrix Product States (cMPS) cannot express the continuum limit state of any Matrix Product State (MPS), according to a certain natural defini…
Mixed states in one spatial dimension: decompositions and correspondence with nonnegative matrices
Gemma De las Cuevas, Tim Netzer
We study six natural decompositions of mixed states in one spatial dimension: the Matrix Product Density Operator (MPDO) form, the local purification form, the separable decomposit…
Optimal bounds on the positivity of a matrix from a few moments
Gemma de las Cuevas, Tobias Fritz, Tim Netzer
In many contexts one encounters Hermitian operators on a Hilbert space whose dimension is so large that it is impossible to write down all matrix entries in an orthonormal basi…