A variety of tasks in quantum control, ranging from purification and cooling to quantum stabilisation and open-system simulation, rely on the ability to implement a target quantum channel over a specified time interval within prescribed accuracy. This can be achieved by engineering a suitable unitary dynamics of the system of interest along with its environment, which, depending on the available level of control, is fully or partly exploited as a coherent quantum controller . After formalising a controllability framework for completely positive trace-preserving quantum dynamics, we provide sufficient conditions on the environment state and dimension that allow for the realisation of relevant classes of quantum channels, including extreme channels, stochastic unitaries or simply any channel. The results hinge on generalisations of Stinespring’s dilation via a subsystem principle . In the process, we show that a conjecture by Lloyd on the minimal dimension of th… …
A quantum is the smallest possible unit of anything, and Quantum Science is the study of these particles and their application. In other words, we know that all matter is made of atoms, but what is the smallest component of an atom and how does it react to stimuli? That deceptively simple explanation is an introduction to a field of science that is exploding into the disciplines of engineering and technology.
The theory of quantum physics has led many to wonder about the nature of matter. Quantum particles seem to react at times like individual particles and at times like continuous waves. This results in some surprising properties.
One of these, superposition, is the ability of quantum systems to include all possible measurements, and only take on certain characteristics when they are measured.
Entanglement is another property of the particles in which the characteristics of multiple particle systems correlate to one another. When you alter one set of measurements, the entire system changes. At the point where these discoveries intersect known developments in information technologies, new opportunities burst open in computing, navigation, sensing, the ability to do simulations and in other areas. This is a rapidly-morphing science that is changing other disciplines as it grows.
Text source: The Computer Science Degree Hub