Quantum Bit Regeneration
摘要
Decoherence and loss will limit the practicality of quantum cryptography and computing unless successful error correction techniques are developed. To this end, we have discovered a new scheme for perfectly detecting and rejecting the error caused by loss (amplitude damping to a reservoir at T=0), based on using a dual-rail representation of a quantum bit. This is possible because (1) balanced loss does not perform a ``which-path'' measurement in an interferometer, and (2) balanced quantum nondemolition measurement of the ``total'' photon number can be used to detect loss-induced quantum jumps without disturbing the quantum coherence essential to the quantum bit. Our results are immediately applicable to optical quantum computers using single photonics devices.
引用
@article{arxiv.quant-ph/9604031,
title = {Quantum Bit Regeneration},
author = {Isaac L. Chuang and Yoshihisa Yamamoto},
journal= {arXiv preprint arXiv:quant-ph/9604031},
year = {2009}
}
备注
4 pages, postscript only, figures available at http://feynman.stanford.edu/qcomp