Uncomputation
![](http://upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Using_Toffoli_Gates_and_Ancilla_Bits_to_make_a_Not_Gate_with_many_controls.png/400px-Using_Toffoli_Gates_and_Ancilla_Bits_to_make_a_Not_Gate_with_many_controls.png)
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] which states that any garbage register after its use in computation may be considered to have been measured.
References[]
- ^ Aaronson, Scott; Grier, Daniel; Schaeffer, Luke (2015). "The Classification of Reversible Bit Operations". arXiv:1504.05155 [quant-ph].
- ^ 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.
- ^ Nielsen, Michael; Chuang, Isaac. "Quantum Computation and Quantum Information"
Categories:
- Quantum physics stubs
- Quantum information science