Abstract
Engineering a sensor system for detecting an extremely tiny signal such as the gravitational-wave force is a very important subject in quantum physics. A major obstacle to this goal is that, in a simple detection setup, the measurement noise is lower bounded by the so-called standard quantum limit (SQL), which is originated from the intrinsic mechanical back-action noise. Hence, the sensor system has to be carefully engineered so that it evades the back-action noise and eventually beats the SQL. In this paper, based on the well-developed geometric control theory for classical disturbance decoupling problem, we provide a general method for designing an auxiliary (coherent feedback or direct interaction) controller for the sensor system to achieve the above-mentioned goal. This general theory is applied to a typical opto-mechanical sensor system. Also, we demonstrate a controller design for a practical situation where several experimental imperfections are present.
Original language | English |
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Article number | 15 |
Journal | EPJ Quantum Technology |
Volume | 3 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2016 Dec 1 |
Keywords
- Back-action evasion
- Coherent feedback
- Geometric control theory
- Opto-mechanical system
ASJC Scopus subject areas
- Control and Systems Engineering
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering