Efficient error characterization in quantum information processing
Abstract
We describe how to use the fidelity decay as a tool to characterize the errors affecting a quantum information processor through a noise generator Gτ . For weak noise, the initial decay rate of the fidelity proves to be a simple way to measure the magnitude of the different terms in Gτ . When the generator has only terms associated with few-body couplings, our proposal is scalable. We present the explicit protocol for estimating the magnitude of the noise generators when the noise consists of only one- and two-body terms, and describe a method for measuring the parameters of more general noise models. The protocol focuses on obtaining the magnitude with which these terms affect the system during a time step of length τ ; measurement of this information has critical implications for assessing the scalability of fault-tolerant quantum computation in any physical setup.
- Publication:
-
Physical Review A
- Pub Date:
- February 2007
- DOI:
- 10.1103/PhysRevA.75.022314
- arXiv:
- arXiv:quant-ph/0608246
- Bibcode:
- 2007PhRvA..75b2314L
- Keywords:
-
- 03.67.Lx;
- 03.65.Yz;
- 03.67.Pp;
- Quantum computation;
- Decoherence;
- open systems;
- quantum statistical methods;
- Quantum error correction and other methods for protection against decoherence;
- Quantum Physics
- E-Print:
- 11 pages, 9 figures