Battling Decoherence: The Fault‐Tolerant Quantum Computer

JUN 01, 1999

Quantum computers have the potential to do certain calculations faster than any foreseeable classical computers, but their success will depend on preserving complex coherent quantum states. Recent discoveries have shown us how to do that.

DOI: 10.1063/1.882692

John Preskill

Information carried by a quantum system has notoriously weird properties. Physicists and engineers are now learning how to put that weirdness to work. Quantum computers, which manipulate quantum states rather than classical bits, may someday be able to perform tasks that would be inconceivable with conventional digital technology. (See the article by Charles H. Bennett, PHYSICS Today, October 1995, page 24, and the “Search and Discovery” report in PHYSICS Today, March 1996, page 21.)b

References

1. R. P. Feynman, Int. J. Theor. Phys. 21, 467 (1982).https://doi.org/IJTPBM
2. D. Deutsch, Proc. Roy. Soc. London, Ser. A 400, 96 (1985).
3. P. Shor, in Proc. of the 35th Annual Symp. on Foundations of Computer Science, Los Alamitos, Calif., IEEE Press (1994), p. 124.
4. D. Dieks, Phys. Lett. A 92, 271 (1982).
W. K. Wootters, W. H. Zurek, Nature 299, 802 (1982).https://doi.org/NATUAS
5. P. Shor, Phys. Rev. A 52, 2493 (1995).https://doi.org/PLRAAN
6. A. M. Steane, Phys. Rev. Lett. 77, 793 (1996).https://doi.org/PRLTAO
7. R. Laflamme, C. Miquel, J. P. Paz, W. Zurek, Phys. Rev. Lett. 77, 198 (1996). https://doi.org/PRLTAO
C. Bennett, D. DiVincenzo, J. Smolin, W. Wootters, Phys. Rev. A 54, 3824 (1996).https://doi.org/PLRAAN
8. A. R. Calderbank, P. W. Shor, Phys. Rev. A 54, 1098 (1996). https://doi.org/PLRAAN
A. M. Steane, Proc. Roy. Soc. London, Ser A 452, 2551 (1996).
9. P. Shor, in Proc. of the 37th Annual Symp. on Foundations of Computer Science, Los Alamitos, Calif., IEEE Press (1996), p. 56.
10. E. Knill, R. Laflamme, preprint, http://xxx.lanl.gov/abs/quant‐ph/9608012.
11. E. Knill, R. Laflamme, W. Zurek, Proc. Roy. Soc. London, Ser. A 454, 365 (1998). https://doi.org/PRLAAZ
A. Yu. Kitaev, Russ. Math. Surveys 52, 1191 (1997). https://doi.org/RMSUAF
D. Aharonov, M. Ben‐Or, in Proc. of the 29th Annual ACM Symp. on the Theory of Computing, New York, ACM (1997), p. 176
J. Preskill, Proc. Roy. Soc. London, Ser. A 454, 385 (1998).https://doi.org/PRLAAZ
12. A. Yu. Kitaev, preprint, http://xxx.lanl.gov/abs/quant‐ph/9707021.
J. Preskill, preprint, http://xxx.lanl.gov/abs/quant‐ph/9712048.
13. D. G. Cory, M. D. Price, W. Maas, E. Knill, R. Laflamme, W. H. Zurek, T. F. Havel, S. S. Samaroo, Phys. Rev. Lett. 81, 2152 (1998).https://doi.org/PRLTAO
14. D. Leung, L. Vandersypen, X. Zhou, M. Sherwood, C. Yannoni, M. Kubinec, I. Chuang, preprint, http://xxx.lanl.gov/abs/quant‐ph/9811068.
15. C. Monroe, D. M. Meekhof, B. E. King, W. M. Itano, D. J. Wineland, Phys. Rev. Lett. 75, 4714 (1995). https://doi.org/PRLTAO
Q. A. Turchette, C. J. Hood, W. Lange, H. Mabuchi, H. J. Kimble, Phys. Rev. Lett. 75, 4710 (1995).https://doi.org/PRLTAO

More about the Authors

John Preskill. Caltech.