Specialty Grand Challenge: Quantum engineering

During the last century, the term “quantum engineering” has adopted very different meanings. In early appearances it often implied the construction quantum systems—e.g., engineering of optical properties through controlled quantum dynamics (Rosencher et al., 1996), atom-by-atom design of nanostructures (Fernández Rossier, 2013), or hybridization of existing quantum objects (Wallquist et al., 2009)—or to the preparation of specific quantum states—e.g., engineering of intrinsically quantum states in trapped ions (Poyatos et al., 1997) or cavity-QED setups (Haroche, 1999). More recently, the quantum engineering have begun to denote a field of reserach, covering either narrow scopes around quantum information tasks (Smith, 2018; Asfaw et al., 2022) or a very broad description that includes all quantum technologies (Dzurak et al., 2022). In this work we refer to quantum engineering as the field devoted to the fabrication, control and characterization of quantum systems with an intrinsically quantum dynamics. In this sense, quantum engineering traverses all areas of quantum technologies, including communication, computing, simulation, metrology and sensing, and also impacts other areas of basic and applied science, where the control of the quantum dynamics and quantum systems brings out new phenomena. Quantum engineering uses the language of quantum information science as a toolbox to understand and design complex quantum states and quantum operations, but it also builds on the tools from quantum control, quantum optics and many-body physics. Inspired by other areas of engineering, as in the work by Zagoskin (2017), one may structure quantum engineering in a bottom-up approach (c.f. Figure 1), according to the degree of complexity of the objects involved: 1) the design and operation of individual quantum units, 2) the engineering of interactions between such units, 3) the combination of those structures into operational devices for communication, computing or sensing, or new emerging structures, 4) and the creation of interfaces between quantum, classical or hybrid devices according to systems engineering. Alternatively, we can focus on the tasks at hand: 1) fabrication, 2) operation and control, and 3) characterization. In the following text we highlight different challenges in several of these possible subdivisions.