Adaptive operations for entanglement distillation and other applications

Advanced protocols of the contemporary quantum information processing rely on non-Gaussian operations such as the single photon subtraction. The current level of technology permits only conditional realizations of such... [ view full abstract ]

Advanced protocols of the contemporary quantum information processing rely on non-Gaussian operations such as the single photon subtraction. The current level of technology permits only conditional realizations of such operations, hindering their usefulness in experimental practice. In our contribution we focus on improving the success rate of these operations using an iterative approach based on recycling the signal until the conditional operation succeeds. We analyse the properties of the improved subtraction procedure in three distinct scenarios. We use the operation to subtract a single photon from a squeezed vacuum state to obtain a maximally non-Gaussian state, we apply the protocol to superposed coherent states to investigate the preservation of quantum superposition, and we employ the improved procedure in a basic quantum entanglement distillation protocol to determine its possible practical impact.