Noise-enhanced performance of adiabatic quantum computing by lifting degeneracies
Abstract
We investigate the symmetry breaking role of noise in adiabatic quantum computing using the example of the controlled-not gate. In particular, we analyze situations where the choice of initial Hamiltonian produces symmetries in the Hamiltonian and degeneracies in the spectrum. We show that, in these situations, the conventional stipulation that the initial and problem Hamiltonians do not commute is unnecessary, as noise will inherently play the role of a universal symmetry-breaking perturbation and split any level crossings that may impede or obstruct the computation. The effects of an artificial noise source with a tailored time-dependent amplitude are also explored and it is found that such a scheme could offer a considerable performance enhancement. These results are found using a generalized version of the Pechukas-Yukawa model of eigenvalue dynamics.
- Publication:
-
Physical Review A
- Pub Date:
- November 2010
- DOI:
- 10.1103/PhysRevA.82.052328
- arXiv:
- arXiv:1002.2574
- Bibcode:
- 2010PhRvA..82e2328W
- Keywords:
-
- 03.67.Lx;
- 03.67.Pp;
- Quantum computation;
- Quantum error correction and other methods for protection against decoherence;
- Quantum Physics
- E-Print:
- 12 pages and 4 figures in preprint format. References in article corrected and journal reference added