Physics – Quantum Physics
Scientific paper
2007-10-08
Phys. Rev. A 78, 012314 (2008)
Physics
Quantum Physics
19 pages, 5 figures. Includes response to arXiv:quant-ph/0702050. New title and an additional example
Scientific paper
10.1103/PhysRevA.78.012314
We analyze the long time behavior of a quantum computer running a quantum error correction (QEC) code in the presence of a correlated environment. Starting from a Hamiltonian formulation of realistic noise models, and assuming that QEC is indeed possible, we find formal expressions for the probability of a faulty path and the residual decoherence encoded in the reduced density matrix. Systems with non-zero gate times (``long gates'') are included in our analysis by using an upper bound on the noise. In order to introduce the local error probability for a qubit, we assume that propagation of signals through the environment is slower than the QEC period (hypercube assumption). This allows an explicit calculation in the case of a generalized spin-boson model and a quantum frustration model. The key result is a dimensional criterion: If the correlations decay sufficiently fast, the system evolves toward a stochastic error model for which the threshold theorem of fault-tolerant quantum computation has been proven. On the other hand, if the correlations decay slowly, the traditional proof of this threshold theorem does not hold. This dimensional criterion bears many similarities to criteria that occur in the theory of quantum phase transitions.
Baranger Harold U.
Mucciolo Eduardo R.
Novais E.
No associations
LandOfFree
Hamiltonian Formulation of Quantum Error Correction and Correlated Noise: The Effects Of Syndrome Extraction in the Long Time Limit does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Hamiltonian Formulation of Quantum Error Correction and Correlated Noise: The Effects Of Syndrome Extraction in the Long Time Limit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hamiltonian Formulation of Quantum Error Correction and Correlated Noise: The Effects Of Syndrome Extraction in the Long Time Limit will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-544699