TY - JOUR
T1 - Quantum Feedback Amplification
AU - Yamamoto, Naoki
N1 - Funding Information:
This work was supported in part by JSPS Grant-in-Aid No.15K06151.
Publisher Copyright:
© 2016 American Physical Society.
PY - 2016/4/19
Y1 - 2016/4/19
N2 - Quantum amplification is essential for various quantum technologies such as communication and weak-signal detection. However, its practical use is still limited due to inevitable device fragility that brings about distortion in the output signal or state. This paper presents a general theory that solves this critical issue. The key idea is simple and easy to implement: just a passive feedback of the amplifier's auxiliary mode, which is usually thrown away. In fact, this scheme makes the controlled amplifier significantly robust, and furthermore it realizes the minimum-noise amplification even under realistic imperfections. Hence, the presented theory enables the quantum amplification to be implemented at a practical level. Also, a nondegenerate parametric amplifier subjected to a special detuning is proposed to show that, additionally, it has a broadband nature.
AB - Quantum amplification is essential for various quantum technologies such as communication and weak-signal detection. However, its practical use is still limited due to inevitable device fragility that brings about distortion in the output signal or state. This paper presents a general theory that solves this critical issue. The key idea is simple and easy to implement: just a passive feedback of the amplifier's auxiliary mode, which is usually thrown away. In fact, this scheme makes the controlled amplifier significantly robust, and furthermore it realizes the minimum-noise amplification even under realistic imperfections. Hence, the presented theory enables the quantum amplification to be implemented at a practical level. Also, a nondegenerate parametric amplifier subjected to a special detuning is proposed to show that, additionally, it has a broadband nature.
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U2 - 10.1103/PhysRevApplied.5.044012
DO - 10.1103/PhysRevApplied.5.044012
M3 - Article
AN - SCOPUS:84973509220
SN - 2331-7019
VL - 5
JO - Physical Review Applied
JF - Physical Review Applied
IS - 4
M1 - 044012
ER -