Loss-error compensation in quantum-state measurements

被引：24

作者：

D'Ariano, GM

Macchiavello, C

机构：

[1] Univ Pavia, Dipartimento Fis Alessandro Volta, I-27100 Pavia, Italy

[2] Univ Pavia, INFM, I-27100 Pavia, Italy

[3] Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England

来源：

PHYSICAL REVIEW A | 1998年 / 57卷 / 04期

关键词：

D O I：

10.1103/PhysRevA.57.3131

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

In the two papers [T. Kiss, U. Herzog, and U. Leonhardt, Phys. Rev. A 52, 2433 (1995); U. Herzog, Phys. Rev. A 53, 1245 (1996)] with titles similar to the one given above, the authors assert that in some cases it is possible to compensate a quantum efficiency eta less than or equal to 1/2 in quantum-state measurements, violating the lower bound 1/2 proved in a preceding paper [G. M. D'Ariano, U. Leonhardt, and H. Paul, Phys. Rev. A 52, R1801 (1995)]. Here we reestablish the bound for homodyning any quantum state, and show how the proposed loss-compensation method would fail in a real measurement outside the eta>1/2 regime.

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收藏

页码：3131 / 3133

页数：3

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