Eigenstate preparation by phase decoherence
- Creators
- Somma, Rolando
- Boixo, Sergio
- Knill, Emanuel
Abstract
A computation in adiabatic quantum computing is implemented by traversing a path of nondegenerate eigenstates of a continuous family of Hamiltonians. We introduce a method that traverses a discretized form of the path: at each step we apply the instantaneous Hamiltonian for a random time. The resulting decoherence approximates a projective measurement onto the desired eigenstate, achieving a version of the quantum Zeno effect. The average cost of our method is O(L^2/Δ) for constant error probability, where L is the length of the path of eigenstates and Δ is the minimum spectral gap of the Hamiltonian. For many cases of interest, L does not depend on Δ so the scaling of the cost with the gap is better than the one obtained in rigorous proofs of the adiabatic theorem. We give an example where this situation occurs.
Additional Information
© 2009 IEEE. We thank H. Barnum for discussions. This work was supported by Perimeter Institute for Theoretical Physics, by the Government of Canada through Industry Canada and by the Province of Ontario through the Ministry of Research and Innovation. This work was also supported by the National Science Foundation under grant PHY-0803371 through the Institute for Quantum Information at the California Institute of Technology. Contributions to this work by NIST, an agency of the US government, are not subject to copyright laws.Attached Files
Published - 05069535.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:41e1bd6fd01f6a239b7318b7b3e3848b
|
219.2 kB | Preview Download |
Additional details
- Eprint ID
- 75492
- Resolver ID
- CaltechAUTHORS:20170328-165309333
- Perimeter Institute for Theoretical Physics
- Industry Canada
- Ontario Ministry of Research and Innovation
- PHY-0803371
- NSF
- Created
-
2017-03-29Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field