2,403 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
Guaranteed Non-quadratic Performance for Quantum Systems with Nonlinear Uncertainties
This paper presents a robust performance analysis result for a class of
uncertain quantum systems containing sector bounded nonlinearities arising from
perturbations to the system Hamiltonian. An LMI condition is given for
calculating a guaranteed upper bound on a non-quadratic cost function. This
result is illustrated with an example involving a Josephson junction in an
electromagnetic cavity.Comment: A version of this paper is to appear in the Proceedings of the 2014
American Control Conferenc
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
Real-time Information, Uncertainty and Quantum Feedback Control
Feedback is the core concept in cybernetics and its effective use has made
great success in but not limited to the fields of engineering, biology, and
computer science. When feedback is used to quantum systems, two major types of
feedback control protocols including coherent feedback control (CFC) and
measurement-based feedback control (MFC) have been developed. In this paper, we
compare the two types of quantum feedback control protocols by focusing on the
real-time information used in the feedback loop and the capability in dealing
with parameter uncertainty. An equivalent relationship is established between
quantum CFC and non-selective quantum MFC in the form of operator-sum
representation. Using several examples of quantum feedback control, we show
that quantum MFC can theoretically achieve better performance than quantum CFC
in stabilizing a quantum state and dealing with Hamiltonian parameter
uncertainty. The results enrich understanding of the relative advantages
between quantum MFC and quantum CFC, and can provide useful information in
choosing suitable feedback protocols for quantum systems.Comment: 24 page
- …