Quantum Computation with Circuit QED Systems

Leo DiCarlo

Xiaozhou Pan, Pengtao Song, Yvonne Y. Gao

Ingrid Strandberg, Fernando Quijandría, Göran Johansson

François Chapeau‐Blondeau

Hayato Goto

Cavity quantum electrodynamics (cavity QED) with microwave photons and superconducting circuits, referred to as circuit QED, has been developed in the past two decades, on which current superconducting quantum computers are largely based. Here we present two kinds of circuit-QED-based quantum computation: bosonic quantum computation using microwave photons in 3D cavities and quantum computation using Kerr-nonlinear parametric oscillators.

Prabin Adhikari, Mohammad Hafezi, Jacob M. Taylor

One approach to quantum information processing is to use photons as quantum bits and rely on linear optical elements for most operations. However, some optical nonlinearity is necessary to enable universal quantum computing. Here, we suggest a circuit-QED approach to nonlinear optics quantum computing in the microwave regime, including a deterministic two-photon phase gate. Our specific example uses a hybrid quantum system comprising a LC resonator coupled to a superconducting flux qubit to implement a nonlinear coupling. Compared to the self-Kerr nonlinearity, we find that our approach has improved tolerance to noise in the qubit while maintaining fast operation.