Progress towards Quantum Fisher Information of the Mach-Zehnder interferometer with losses

We present progress toward determining the Quantum Fisher Information (QFI) for the Mach-Zehnder interferometer with losses. A process for calculating the QFI for high-rank density operators with general non-orthogonal states is introduced. This method is dependent on inverting a matrix of the form (A+I), for which a novel finite series solution is introduced.