English

Protected quantum computation with multiple resonators in ultrastrong coupling circuit QED

Quantum Physics 2011-11-15 v2 Mesoscale and Nanoscale Physics Superconductivity

Abstract

We investigate theoretically the dynamical behavior of a qubit obtained with the two ground eigenstates of an ultrastrong coupling circuit-QED system consisting of a finite number of Josephson fluxonium atoms inductively coupled to a transmission line resonator. We show an universal set of quantum gates by using multiple transmission line resonators (each resonator represents a single qubit). We discuss the intrinsic 'anisotropic' nature of noise sources for fluxonium artificial atoms. Through a master equation treatment with colored noise and manylevel dynamics, we prove that, for a general class of anisotropic noise sources, the coherence time of the qubit and the fidelity of the quantum operations can be dramatically improved in an optimal regime of ultrastrong coupling, where the ground state is an entangled photonic 'cat' state.

Keywords

Cite

@article{arxiv.1106.1159,
  title  = {Protected quantum computation with multiple resonators in ultrastrong coupling circuit QED},
  author = {Pierre Nataf and Cristiano Ciuti},
  journal= {arXiv preprint arXiv:1106.1159},
  year   = {2011}
}

Comments

Added results with N = 3,4,5 Josephson atoms and different anisotropy ratios for the decoherence channels in the new figures 2 and 3

R2 v1 2026-06-21T18:18:32.730Z