English

Decoherence of an $n$-qubit quantum memory

Quantum Physics 2008-01-18 v1

Abstract

We analyze decoherence of a quantum register in the absence of non-local operations i.e. of nn non-interacting qubits coupled to an environment. The problem is solved in terms of a sum rule which implies linear scaling in the number of qubits. Each term involves a single qubit and its entanglement with the remaining ones. Two conditions are essential: first decoherence must be small and second the coupling of different qubits must be uncorrelated in the interaction picture. We apply the result to a random matrix model, and illustrate its reach considering a GHZ state coupled to a spin bath.

Keywords

Cite

@article{arxiv.quant-ph/0703190,
  title  = {Decoherence of an $n$-qubit quantum memory},
  author = {Thomas Gorin and Carlos Pineda and Thomas H. Seligman},
  journal= {arXiv preprint arXiv:quant-ph/0703190},
  year   = {2008}
}

Comments

4 pages, 2 figures