Spectrum analysis with quantum dynamical systems
| Autor: | Ng, Shilin, Ang, Shan Zheng, Wheatley, Trevor A., Yonezawa, Hidehiro, Furusawa, Akira, Huntington, Elanor H., Tsang, Mankei |
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| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Phys. Rev. A 93, 042121 (2016) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevA.93.042121 |
| Popis: | Measuring the power spectral density of a stochastic process, such as a stochastic force or magnetic field, is a fundamental task in many sensing applications. Quantum noise is becoming a major limiting factor to such a task in future technology, especially in optomechanics for temperature, stochastic gravitational wave, and decoherence measurements. Motivated by this concern, here we prove a measurement-independent quantum limit to the accuracy of estimating the spectrum parameters of a classical stochastic process coupled to a quantum dynamical system. We demonstrate our results by analyzing the data from a continuous optical phase estimation experiment and showing that the experimental performance with homodyne detection is close to the quantum limit. We further propose a spectral photon counting method that can attain quantum-optimal performance for weak modulation and a coherent-state input, with an error scaling superior to that of homodyne detection at low signal-to-noise ratios. Comment: 12 pages, 4 figures |
| Databáze: | arXiv |
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