Fast single qubit quantum logic gates

We posted a new paper on the arxiv (, presenting a new quantum control method that we named FIESTA (Floquet Interference Efficient Suppression of Transitions in the Adiabatic basis). This work addresses the implementation of quantum gates with a speed approaching the qubit transition frequency. This is the highest possible speed for quantum control of a qubit and reaching it allows for high fidelity gates, overcoming the effect of decoherence.

New paper on decoherence of flux qubits

A new paper on decoherence of flux qubits,  by Jean-Luc Orgiazzi et al., has been published in Physical Review B. This paper presents a systematic study of decoherence of flux qubits coupled to a superconducting resonator, which is a building block for a scalable architecture for superconducting quantum information processing.


New paper on Arxiv on ultrastrong coupling in a qubit-waveguide system

A new paper is now on the arxiv

Ultrastrong coupling of a single artificial atom to an electromagnetic continuum

Pol Forn-Diaz et al. have observed signatures of ultrastrong coupling between a superconducting flux qubit and the electromagnetic continuum of a one-dimensional waveguide, a transmission line. This work opens the door to study a new regime of quantum optics of single emitters in free space.

The figure below shows the evolution of the qubit spectrum as coupling is increased, with the linewidth growing beyond the qubit frequency, a signature of ultrastrong coupling.