A Direct Coupling Coherent Quantum Observer for an Oscillatory Quantum Plant

A direct coupling coherent observer is constructed for a linear quantum plant which has oscillatory solutions. It is shown that a finite time moving average of the quantum observer output can provide an estimate of the quantum plant output without disturbing this plant signal. By choosing a sufficiently small averaging time and a sufficiently large observer gain, the observer tracking error can be made arbitrarily small.This work was supported by the Air Force Office of Scientific Research (AFOSR), under agreement number FA2386-16-1-4065. Some of the research presented in this paper was also supported by the Australian Research Council under grant FL110100020

Time averaged consensus in a direct coupled coherent quantum observer network

This paper considers the problem of constructing a direct coupling quantum observer for a closed linear quantum system. The proposed distributed observer consists of a network of quantum harmonic oscillators and it is shown that the observer network converges to a consensus in a time averaged sense in which each element of the observer estimates the specified output of the quantum plant. An example and simulations are included to illustrate the properties of the observer networkThis work was supported by the Air Force Office of Scientific Research (AFOSR), under agreement number FA2386-16-1-4065. Some of the research presented in this paper was also supported by the Australian Research Council under grant FL110100020

A Direct Coupling Coherent Quantum Observer for a Qubit, including Observer Measurements

This paper proposes a direct coupling coherent quantum observer for a quantum plant which consists of a two level quantum system. The quantum observer, which is a quantum harmonic oscillator, includes homodyne detection measurements. It is shown that the observer can be designed so that it does not affect the quantum variable of interest in the quantum plant and that measured output converges in a given sense to the plant variable of interest. Also, the plant variable of interest-observer system can be described by a set of linear quantum stochastic differential equations. A minimum variance unbiased estimator form of the Kalman filter is derived for linear quantum systems and applied to the direct coupled coherent quantum observerThis work was supported by the Australian Research Council(ARC) under grant FL110100020 and the Air Force Office of Scientific Research(AFOSR),under agreement number FA2386-16-1-4065

Coherent quantum observers for n-level quantum systems

The purpose of this paper is to find coherent quantum observers for open n-level quantum systems. Recently, a class of linear coherent observers has been developed for quantum harmonic oscillators. However, open n-level quantum systems, which are charact