Jump to content

Uncomputation

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by Sterngerlach (talk | contribs) at 22:40, 7 May 2022. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Creating a logical conjunction of the five controls out of Toffoli gates and ancilla bits. Uncomputation is used to restore the ancilla bits to their original states before finishing.

Uncomputation is a technique, used in reversible circuits, for cleaning up temporary effects on ancilla bits so that they can be re-used.[1]

Uncomputation is a fundamental step in quantum computing algorithms. Whether or not intermediate effects have been uncomputed affects how states interfere with each other when measuring results.[2]

The process is primarily motivated by the principle of implicit measurement,[3] since entanglement with garbage registers may induce unintentional side-effects such as wavefunction collapse in other quantum registers.

References

  1. ^ Aaronson, Scott; Grier, Daniel; Schaeffer, Luke (2015). "The Classification of Reversible Bit Operations". arXiv:1504.05155 [quant-ph].
  2. ^ Aaronson, Scott (2002). "Quantum Lower Bound for Recursive Fourier Sampling". Quantum Information and Computation ():, 00. 3 (2): 165–174. arXiv:quant-ph/0209060. Bibcode:2002quant.ph..9060A.
  3. ^ Nielsen, Michael; Chuang, Isaac. "Quantum Computation and Quantum Information"