Quadrature Histograms in Maximum Likelihood Quantum State Tomography
Leonardo E. Silva, Scott C. Glancy, Hilma H. Macedo De Vasconcelos
Quantum state tomography aims to determine the quantum state of a system from measured data and is an essential tool for quantum information science. When dealing with continuous variable quantum states of light, tomography is often done by measuring the field amplitudes at different optical phases using homodyne detection. The quadrature-phase homodyne measurement outputs a continuous variable, so to reduce the computational cost of tomography, researchers often discretize the measurements into histogram bin. We show that this can be done without significantly degrading the fidelity of the estimated state. This paper tests different strategies for determining the histogram bin widths. We show that computation time can be significantly reduced with little fidelity loss when the measurement operators corresponding to each histogram bin are integrated over the bin width.