Advantages of nonclassical pointer states in postselected weak measurements
| Autor: | Yusuf Turek, Wulayimu Maimaiti, Mohammad Al-Amri, Chang-Pu Sun, Yutaka Shikano |
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| Rok vydání: | 2015 |
| Předmět: |
Physics
Quantum Physics FOS: Physical sciences 81P15 Interaction strength Semiclassical physics Mathematical Physics (math-ph) Quantum fisher information Atomic and Molecular Physics and Optics Measurement theory Quantum mechanics Pointer (computer programming) Weak measurement Quantum information Quantum Physics (quant-ph) Mathematical Physics Optics (physics.optics) Physics - Optics |
| Zdroj: | Physical Review A. 92 |
| ISSN: | 1094-1622 1050-2947 |
| DOI: | 10.1103/physreva.92.022109 |
| Popis: | We investigate, within the weak measurement theory, the advantages of non-classical pointer states over semi-classical ones for coherent, squeezed vacuum, and Schr\"{o}inger cat states. These states are utilized as pointer state for the system operator $\hat{A}$ with property $\hat{A}^{2}=\hat{I}$, where $\hat{I}$ represents the identity operator. We calculate the ratio between the signal-to-noise ratio (SNR) of non-postselected and postselected weak measurements. The latter is used to find the quantum Fisher information for the above pointer states. The average shifts for those pointer states with arbitrary interaction strength are investigated in detail. One key result is that we find the postselected weak measurement scheme for non-classical pointer states to be superior to semi-classical ones. This can improve the precision of measurement process. Comment: 8 pages, 5 figures |
| Databáze: | OpenAIRE |
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