Abstract

This will be a review of research on superconducting quantum circuits. Since the first demonstration of quantum coherence in a solid-state device [1], there has been enormous progress in the field with the qubit properties improving steadily [2]. While there is still a long way to go before a practical quantum processor will be built, qubits may find applications in areas other than quantum computation. Examples include quantum-limited detection and on-chip quantum optics experiments.

I will start with a brief introduction of generic qubits and superconducting qubits in particular, and describe a variety of superconducting qubits based on different degrees of freedom. Then I will introduce a circuit QED architecture [3] which is uniquely suited for probing quantum properties of macroscopic mechanical objects and also for on-demand single-photon generation in the microwave domain. Recent joint activity of Lancaster and its collaborators will be discussed [4].

[1] Y. Nakamura, Yu.A. Pashkin, J.S. Tsai, Nature 398, 305 (1999); [2] M.H. Devoret and R.J. Schoelkopf, Science 339, 1169 (2013); [3] A. Wallraff et al., Nature 431, 162 (2004); [4] R. George et al, quant-ph arXiv:1609.07057.