Toward engineering design of quantum circuits

Summary A new engineering discipline called ‘quantum technology’ is emerging. Nanotechnology and cryotechnology enable engineers to develop devices and integrated circuits in which quantum phenomena have dominant sway. Macroscopic finite-state ‘artificial atoms’ are realized exploiting superconductive Josephson effect, and these ‘atoms’ exchange microwave photons in superconductive microwave circuits. The achievements of cavity quantum electrodynamics in quantum optics are mimicked in the microwave frequency range. The new technology is dubbed circuit quantum electrodynamics. This paper tries to call the attention of engineers majoring in circuit theory and design on the challenges they face in designing quantum circuits. Modeling and simulation of quantum circuit components are reviewed. Approximate closed quantum system models as well as more accurate open system models are introduced in the case of single quantum devices and composite quantum systems. The effects of amplitude damping and phase damping are illustrated by simulation. The role of classical resistors in quantum circuits is investigated. Special attention is given to the almost standardized technology developed for superconductive microwave quantum circuits. Open problems are identified that circuit designers face in developing computer-aided-design tools for quantum circuits. Copyright © 2017 John Wiley & Sons, Ltd.