Heisenberg-limit interferometry with four-wave mixers operating in a nonlinear regime
Heisenberg-limit interferometry with four-wave mixers operating in a nonlinear regime
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DOI：
10.1103/physreva.61.043811
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发表时间：
2000-04-01
影响因子：
2.9
通讯作者：
Gerry, CC
中科院分区：
文献类型：
--
作者：
Gerry, CC
Yurke和Stoler[物理学家]研究了在非线性状态下工作的四波混频器模型。Rev. A 35, 4846(1987)]，被重新审查。Yurke和Stoler已经证明，在一定条件下，该装置可以作为奇偶滤波器，将偶光子数状态从泵浦模式切换到信号模式。将泵浦中的初始相干态转换为输出信号和泵浦模式中具有真空态的奇偶相干态纠缠态。我们指出，在不同的条件下，当泵浦初始为偶光子数态，信号为真空时，器件会在数态和真空之间产生最大纠缠态。用该器件代替Mach-Zehnder干涉仪的第一分束器，可以获得海森堡极限（δ phi= 1/n）下的相位不确定度。由于数态难以生成，我们指出，从一个器件的输出获得的偶相干态可以作为另一个器件的输入，以实现相位不确定性δ phi= 1/n(e)，其中n(e)是偶相干态的平均光子数。
A model of a four-wave mixer operated in a nonlinear regime, studied by Yurke and Stoler [Phys. Rev. A 35, 4846 (1987)], is reexamined. Yurke and Stoler have shown that this device, under a certain condition, acts as an even-odd filter, switching even-photon-number states from the pump mode to the signal mode. An initial coherent state in the pump is converted into an entanglement of even and odd coherent, states with vacuum states in the output signal and pump modes. We point out that under a different condition and with an even-photon-number state initially in the pump and a vacuum in the signal, the device creates a maximally entangled state between the number state and the vacuum. Using the device to replace the first beamsplitter of a Mach-Zehnder interferometer, phase uncertainties at the Heisenberg limit (Delta phi= 1/n) can be obtained. Since number states are difficult to generate, we point out that an even coherent state obtained from the output of one device can be used as input to a second to achieve the phase uncertainties Delta phi= 1/n(e), where n(e) is the average photon number of the even coherent state.