Quantum Error Correction: Theory and Experiment

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Driven by curiosity, physicists try to understand the world around us through the properties of nature. Once we have a certain understanding, we begin to be able to predict the behavior of systems with these properties and then gain the ability to control them. Once control is achieved, it is sometimes possible to develop technologies based on these phenomena. Some of these not only have profound impact on our society, they also lay down the basis for this cycle to repeat itself by providing the ability to explore other natural properties at a different scale or complexity. Looking at the past, fire, steam and electro-magnetism are examples of these properties. Turning towards the future, there are many hints that quantum mechanical phenomena will play a similar role.******Quantum information processing promises not only new insight on quantum mechanics but also new technologies with unparalleled power. A critical requirement for these technologies is an exquisite control of quantum systems. Although physicists have developed some control methods and applied them to some quantum systems in the past, they were not scalable, i.e., as the number of quantum bits is increased the required resources would increase exponentially. In the mid-1990s the landscape changed dramatically with the discovery of quantum error correction. Fault-tolerant quantum error correction is a theory that allows for sufficient control of quantum systems to solve problems using reasonable resources, as long as the error rate is below a threshold. My work builds on this theory (that I have helped create) with an aim to turning concepts into practical implementations. My work in quantum error correction encompasses both theoretical and experimental investigations.******There are four elements needed to implement fault tolerant quantum error correction: a specific encoding, having sufficient control, characterizing the type of noise, and extracting entropy of corrupted qubits. My work will contribute to these four areas with the goal of demonstrating many rounds of quantum error correction that protects quantum information against its natural noise. The work will include developing new codes, new methods to assess the noise and use them to improve quantum control as much aas possible and finally work on algorithmic cooling a methods that allows to extract entropy from a set of corrupted qubits. My work will encompasses both theoretical and experimental investigations.**