Superconducting Quantum Circuits for Quantum Computing and Quantum Simulation

Frank K. Wilhelm

Alan M. Kadin

•Classical superconducting circuit simulators are powerful and available. •Include Josephson junction as basic element. •Provide efficient time-domain simulations of complex circuits. •May show effects otherwise attributed to quantum circuits. •Circuits of coupled superconducting qubits are being developed for quantum computing (QC). •Entangled quantum theory incompatible with classical simulators. •Quantum model difficult to simulate on conventional computers for complex circuits already being tested. •Classical circuit simulations should provide the baseline to compare with quantum effects, but this is seldom done. •Coupled oscillators are delocalized even in classical limit.

David P. Pappas, Hsiang‐Sheng Ku, Junling Long +9 more

Prabin Adhikari

Superconducting quantum circuits are a promising approach for realizations of large scale quantum information processing and quantum simulations. The Josephson junction, which forms the basis of superconducting circuits, is the only known nonlinear non-dissipative circuit element, and its inherent nonlinearities have found many different applications. In this thesis I discuss specific implementations of these circuits. I show that strong two-photon nonlinearities can be induced by coupling photons in the microwave domain to Josephson nonlinearities. I then propose a method to simulate a parent Hamiltonian that can potentially be used to observe fractional quantum Hall states of light. I will also explore how superconducting circuits can be used to modify system-bath couplings to emulate a chemical potential for photons. Finally, I consider the limitations of devising a scheme to couple superconducting circuits to trapped ions, and consider the challenges for such hybrid approaches.

Juan José García‐Ripoll

Superconducting quantum circuits are among the most promising solutions for the development of scalable quantum computers. Built with sizes that range from microns to tens of metres using superconducting fabrication techniques and microwave technology, superconducting circuits demonstrate distinctive quantum properties such as superposition and entanglement at cryogenic temperatures. This book provides a comprehensive and self-contained introduction to the world of superconducting quantum circuits, and how they are used in current quantum technology. Beginning with a description of their basic superconducting properties, the author then explores their use in quantum systems, showing how they can emulate individual photons and atoms, and ultimately behave as qubits within highly connected quantum systems. Particular attention is paid to cutting-edge applications of these superconducting circuits in quantum computing and quantum simulation. Written for graduate students and junior researchers, this accessible text includes numerous homework problems and worked examples.

Leszek Jaroszynski