Engineering dissipative channels for realizing Schrödinger cats in SQUIDs

We show that by engineering the interaction with the environment, there exists a large class of systems that can evolve irreversibly to a cat state. To be precise, we show that it is possible to engineer an irreversible process so that the steady state is close to a pure Schrödinger’s cat state by using double well systems and an environment comprising two-photon (or phonon) absorbers.We also show that it should be possible to prolong the lifetime of a Schrödinger’s cat state exposed to the destructive effects of a conventional single-photon decohering environment. In addition to our general analysis, we present a concrete circuit realization of both system and environment that should be fabricatable with current technologies. Our protocol should make it easier to prepare and maintain Schrödinger cat states, which would be useful in applications of quantum metrology and information processing as well as being of interest to those probing the quantum to classical transition

Quantum systems engineering: a structured approach to accelerating the development of a quantum technology industry

The exciting possibilities in the field of new quantum technologies extend far beyond the well-reported application of quantum computing. Precision timing, gravity sensors and imagers, cryptography, navigation, metrology, energy harvesting and recovery, biomedical sensors and imagers, and real-time optimisers all indicate the potential for quantum technologies to provide the basis of a technological revolution. From the field of Systems Engineering emerges a focused strategy for the development cycle, enabling the existence of hugely complex products. It is through the adoption of systems thinking that the semiconductor industry has achieved massive industrial and economic impact. Quantum technologies rely on delicate, non-local and/or entangled degrees of freedom — leading to great potential, but also posing new challenges to the development of products and industries. We discuss some of the challenges and opportunities regarding the implementation of Systems Engineering and systems thinking into the quantum technologies space

Quantum systems engineering

With the aim of defining a Quantum Systems Engineering paradigm, we show that the systems engineering of quantum technologies is materially different from systems engineering in general. The thesis is based upon a two pronged mixed-methods research approach considering: (a) a comprehensive theoretical analysis of the difficulties in deriving systems engineering modelling tools; (b) identifying systems engineering challenges in practical quantum technology development through direct observation and case-study methods. We show a modified systems approach should benefit early stage quantum technologies design and development, a stage characterised by a low Technology Readiness Level (TRL), with the aim of accelerating capitalisation. The research showed that systems engineering applied to quantum technologies will require processes that are both more complex, and different from, those used for conventional systems technology development. This is fundamentally caused by the quantum properties of the system. Furthermore, the research evidenced that applying systems methods, tools, and approaches to low Technology Readiness Level development, both quantum and classical, is very likely to accelerate development, increase the quality of deliverables, and improve the alignment of early research to end-user needs and natural technology pull. Based on these results we have developed a series of recommendations, and a selection of systems tools, which together constitute a light-weight systems approach for low Technology Readiness Level development (some of which also apply to non-quantum domains). These are contained within the concluding chapter of the report. Findings are presented both as a verbal narrative and with full mathematical derivations