4,961 research outputs found
Robust Stability of Quantum Systems with Nonlinear Dynamic Uncertainties
This paper considers the problem of robust stability for a class of uncertain
nonlinear quantum systems subject to unknown perturbations in the system
Hamiltonian. The nominal system is a linear quantum system defined by a linear
vector of coupling operators and a quadratic Hamiltonian. This paper extends
previous results on the robust stability of nonlinear quantum systems to allow
for quantum systems with dynamic uncertainties. These dynamic uncertainties are
required to satisfy a certain quantum stochastic integral quadratic constraint.
The robust stability condition is given in terms of a strict bounded real
condition. This result is applied to the robust stability analysis of an
optical parametric amplifier.Comment: A shortened version is to appear in the proceedings of the 2013 IEEE
Conference on Decision and Contro
Quantum control theory and applications: A survey
This paper presents a survey on quantum control theory and applications from
a control systems perspective. Some of the basic concepts and main developments
(including open-loop control and closed-loop control) in quantum control theory
are reviewed. In the area of open-loop quantum control, the paper surveys the
notion of controllability for quantum systems and presents several control
design strategies including optimal control, Lyapunov-based methodologies,
variable structure control and quantum incoherent control. In the area of
closed-loop quantum control, the paper reviews closed-loop learning control and
several important issues related to quantum feedback control including quantum
filtering, feedback stabilization, LQG control and robust quantum control.Comment: 38 pages, invited survey paper from a control systems perspective,
some references are added, published versio
Quantum Robust Stability of a Small Josephson Junction in a Resonant Cavity
This paper applies recent results on the robust stability of nonlinear
quantum systems to the case of a Josephson junction in a resonant cavity. The
Josephson junction is characterized by a Hamiltonian operator which contains a
non-quadratic term involving a cosine function. This leads to a sector bounded
nonlinearity which enables the previously developed theory to be applied to
this system in order to analyze its stability.Comment: A version of this paper appeared in the proceedings of the 2012 IEEE
Multi-conference on Systems and Contro
Coherent-Classical Estimation for Quantum Linear Systems
This paper introduces a problem of coherent-classical estimation for a class
of linear quantum systems. In this problem, the estimator is a mixed
quantum-classical system which produces a classical estimate of a system
variable. The coherent-classical estimator may also involve coherent feedback.
An example involving optical squeezers is given to illustrate the efficacy of
this idea.Comment: A version of this paper will appear in the Proceedings of the 2013
Australian Control Conferenc
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