The role of theory in the laboratory control of quantum dynamics phenomena

HERSCHEL A. RABITZ

Interest in the control of quantum dynamics phenomena has grown in recent years, with laboratory studies showing increasing successes. The role of theory in the control of quantum phenomena encompasses the design of laser controls, the development of algorithms to guide the laboratory studies, and the means to analyze the ensuing dynamics observations. Laboratory laser control instrumentation has the special capability of performing massive numbers of experiments in a short period of time, to rapidly search for controls that meet the objectives. This unique laboratory feature needs to be factored in when considering how to best utilize theoretical analyses. The present paper reviews the role that theory is playing, as well as suggests some future avenues for theory in the laser control of quantum phenomena.

HERSCHEL A. RABITZ, Abhra Mitra

HERSCHEL A. RABITZ, Gabriel Turinici, Eric Brown

Herschel H. Rabitz

This paper gives an overview of the logic behind current conceptual issues directed towards controlling quantum phenomena. The role of theory to translate these concepts into laboratory designs will be highlighted, along with an explanation of the complexities of achieving realistic designs. As a result, it will be argued that closed-loop feedback control of quantum dynamics in the laboratory is not only feasible, but will typically be a necessity for the achievement of practical control over quantum phenomena.

Domenico D’Alessandro

HERSCHEL A. RABITZ

Most quantum systems considered for control by external fields are plagued by a serious lack of complete information about the underlying Hamiltonian. Traditional feedback control techniques are generally not appropriate due to the latter problem, as well as the ultrafast nature of typical quantum dynamics phenomena and the fact that observations of the quantum system will inevitably lead to a disturbance which may often be contradictory to the desired control. In contrast, learning control techniques have a special role to play in the manipulation of quantum dynamics phenomena. The unique capabilities of quantum systems making them amenable to learning control are (a) the ability to have very large numbers of identical systems for submission to control, (b) the high duty cycle of laboratory laser controls, and (c) the ability to observe the impact of trial controls at ultrafast time scales. Various learning algorithms have been proposed to guide this control process. The paper discusses these proposals, as well as some new perspectives.