Three-way noiseless signal splitting in a parametric amplifier with quantum correlation

We demonstrate that a phase-insensitive parametric amplifier, when coupled to a quantum correlated source, can be used as a quantum information tap for noiseless three-way signal splitting. We find that the output signals are amplified noiselessly in two of the three output ports, while the other can more or less keep its original input size without adding noise. This scheme can be cascaded and scaled up for efficient information distribution in an optical network. Furthermore, we find that this scheme satisfies the criteria for a nonideal quantum nondemolition (QND) measurement and thus can serve as a QND measurement device. With two readouts correlated to the input, we find this scheme also satisfies the criterion for a sequential QND measurement.