Modelling and feedback control design for quantum state preparation

The goal of this article is to provide a largely self-contained introduction to the modelling of controlled quantum systems under continuous observation, and to the design of feedback controls that prepare particular quantum states. We describe a bottom-up approach, where a field-theoretic model is subjected to statistical inference and is ultimately controlled. As an example, the formalism is applied to a highly idealized interaction of an atomic ensemble with an optical field. Our aim is to provide a unified outline for the modelling, from first principles, of realistic experiments in quantum control

Feedback control of quantum state reduction

Feedback control of quantum mechanical systems must take into account the probabilistic nature of quantum measurement. We formulate quantum feedback control as a problem of stochastic nonlinear control by considering separately a quantum filtering problem and a state feedback control problem for the filter. We explore the use of stochastic Lyapunov techniques for the design of feedback controllers for quantum spin systems and demonstrate the possibility of stabilizing one outcome of a quantum measurement with unit probability

Quantum feedback and adaptive measurements

Summary form only given. Although real-time feedback of measured signals is an essential component of sensing and control in classical settings, models for quantum feedback that are rigorous yet useful have only become possible since the advent of measurement-based quantum trajectory theory. The quantum feedback scenario introduces new concerns of coherence and measurement backaction, but recent work has shown that these can be treated properly in a formal integration of quantum trajectory theory with standard state-space formulations of filtering and control theory. Pioneering studies by H. M. Wiseman have shown that such models can be used to design and to analyze realistic schemes for adaptive homodyne measurement and for feedback control of atomic motion. Much of the ongoing research in our group focuses on the experimental implementation of such schemes. For a broad range of quantum feedback scenarios, certain recurring technical issues arise out of the need to perform complex, high-bandwidth processing of measured signals. We are developing a "rapid-prototyping" approach to refining signal processing and feedback algorithms via quantum trajectory simulation on a PC, followed by translation of the algorithms into hardware Description language (HDL)

Texas Business Review, November 1975

The Business Situation in Texas; Marketing in Mexico; Texas Construction: Using Solar EnergyBureau of Business Researc

An Analysis of Insurable Interest Under Article Two of the Uniform Commercial Code

The basic requisite of an insurable interest pervades all types of insurance contracts.\u27 The reason most commonly given to justify this requirement is that in the absence of such an interest the agreement is no more than a common wager. A second reason is that the absence of an insurable interest might encourage the insured willfully to destroy the property (or life) of the insured. Despite universal recognition of its need, insurable interest is a term of indefinite meaning. This is evidenced by the many opinions in which courts have had difficulty in determining the existence of such an interest. Definitions of the term necessarily are broad and largely useless in the solution of cases. The purpose of all property insurance is to indemnify the insured for casualty to the insured property. If the insured has an insurable interest there is some risk of loss to him in case of casualty to the property, and this risk may be shifted to the insurer. If, on the other hand, there is no risk of loss to shift, there is no insurable interest

Robust quantum parameter estimation: coherent magnetometry with feedback

We describe the formalism for optimally estimating and controlling both the state of a spin ensemble and a scalar magnetic field with information obtained from a continuous quantum limited measurement of the spin precession due to the field. The full quantum parameter estimation model is reduced to a simplified equivalent representation to which classical estimation and control theory is applied. We consider both the tracking of static and fluctuating fields in the transient and steady state regimes. By using feedback control, the field estimation can be made robust to uncertainty about the total spin number

Texas Business Review, August 1967

The Business Situation in Texas; Climatology at Work in Texas; Texas Building Construction, January-June 1967; Texas Retail Sales, January-June 1967Bureau of Business Researc

Medical planning for military operations other then [i.e. than] war: Is a paradigm shift required?

Military operations other than war are increasing in frequency and, as one might surmise present unique challenges to the operational commander and the medical planner. Over time and by necessity the U.S. military has developed a logistical support system with unprecedented capability. This logistical system includes a medical system that is increasingly called upon to provide care to people outside the normal scope. Increased participation means Navy assets will be tasked to provide care to U.S. troops, U.N. troops, multinational troops, NGO personnel, and the civilians that precipitated the need for intervention in the first place. The current planning paradigm is rightfully focused on combat support. This thesis will investigate the necessity of breaking away from that paradigm when planning MOOTW.http://archive.org/details/medicalplanningf109459791Lieutenant, United States NavyApproved for public release; distribution is unlimited