New pre-print “Quantum Tensor Product Decomposition from Choi State Tomography”
In our new pre-print, we study the entangling features of a unitary quantum operation using its operator-Schmidt, or tensor product decomposition. We present an algorithm for unbalanced partitions into a small subsystem and a large one (the environment) that computes the tensor product decomposition of a unitary whose effect on the small subsystem is captured in classical memory while the effect on the environment is accessible as a quantum resource. This quantum algorithm may be used to make predictions about operator non-locality, effective open quantum dynamics on a subsystem, as well as for finding low-rank approximations and low-depth compilations of quantum circuit unitaries.