Amplifier is at the heart of experiments carrying out the precise measurement of a weak signal. An idea quantum amplifier should have a large gain and minimum added noise simultaneously. Here, we consider the quantum ...Amplifier is at the heart of experiments carrying out the precise measurement of a weak signal. An idea quantum amplifier should have a large gain and minimum added noise simultaneously. Here, we consider the quantum measurement properties of the cavity with the OPA medium in the op-amp mode to amplify an input signal. We show that our nonlinear-cavity quantum amplifier has large gain in the single-value stable regime and achieves quantum limit unconditionally.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.11365006,11364006the Natural Science Foundation of Guizhou Province QKHLHZ[2015]7767
文摘Amplifier is at the heart of experiments carrying out the precise measurement of a weak signal. An idea quantum amplifier should have a large gain and minimum added noise simultaneously. Here, we consider the quantum measurement properties of the cavity with the OPA medium in the op-amp mode to amplify an input signal. We show that our nonlinear-cavity quantum amplifier has large gain in the single-value stable regime and achieves quantum limit unconditionally.