### Abstract

Quantum amplifier is an essential device in quantum information processing. As in the classical (non-quantum) case, its characteristic uncertainty needs to be suppressed by feedback, and in fact such a control theory for a single quantum amplifier has recently been developed. This letter extends this result to the case of cascaded quantum amplifier. In particular, we consider two types of structures: the case where controlled amplifiers are connected in series, and the case where a single feedback control is applied to the cascaded amplifier. Then, we prove that the latter is better in the sense of sensitivity to the uncertainty. A detailed numerical simulation is given to show actual performance of these two feedback schemes.

Original language | English |
---|---|

Article number | 8424461 |

Pages (from-to) | 156-161 |

Number of pages | 6 |

Journal | IEEE Control Systems Letters |

Volume | 3 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2019 Jan 1 |

### Fingerprint

### Keywords

- Quantum information and control
- robust control
- stability of linear systems

### ASJC Scopus subject areas

- Control and Systems Engineering
- Control and Optimization

### Cite this

*IEEE Control Systems Letters*,

*3*(1), 156-161. [8424461]. https://doi.org/10.1109/LCSYS.2018.2862620

**Sensitivity Analysis of Cascaded Quantum Feedback Amplifier.** / Yokotera, Yu; Yamamoto, Naoki.

Research output: Contribution to journal › Article

*IEEE Control Systems Letters*, vol. 3, no. 1, 8424461, pp. 156-161. https://doi.org/10.1109/LCSYS.2018.2862620

}

TY - JOUR

T1 - Sensitivity Analysis of Cascaded Quantum Feedback Amplifier

AU - Yokotera, Yu

AU - Yamamoto, Naoki

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Quantum amplifier is an essential device in quantum information processing. As in the classical (non-quantum) case, its characteristic uncertainty needs to be suppressed by feedback, and in fact such a control theory for a single quantum amplifier has recently been developed. This letter extends this result to the case of cascaded quantum amplifier. In particular, we consider two types of structures: the case where controlled amplifiers are connected in series, and the case where a single feedback control is applied to the cascaded amplifier. Then, we prove that the latter is better in the sense of sensitivity to the uncertainty. A detailed numerical simulation is given to show actual performance of these two feedback schemes.

AB - Quantum amplifier is an essential device in quantum information processing. As in the classical (non-quantum) case, its characteristic uncertainty needs to be suppressed by feedback, and in fact such a control theory for a single quantum amplifier has recently been developed. This letter extends this result to the case of cascaded quantum amplifier. In particular, we consider two types of structures: the case where controlled amplifiers are connected in series, and the case where a single feedback control is applied to the cascaded amplifier. Then, we prove that the latter is better in the sense of sensitivity to the uncertainty. A detailed numerical simulation is given to show actual performance of these two feedback schemes.

KW - Quantum information and control

KW - robust control

KW - stability of linear systems

UR - http://www.scopus.com/inward/record.url?scp=85057643556&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85057643556&partnerID=8YFLogxK

U2 - 10.1109/LCSYS.2018.2862620

DO - 10.1109/LCSYS.2018.2862620

M3 - Article

AN - SCOPUS:85057643556

VL - 3

SP - 156

EP - 161

JO - IEEE Control Systems Letters

JF - IEEE Control Systems Letters

SN - 2475-1456

IS - 1

M1 - 8424461

ER -