Turbo-charging the Adiabatic Quantum Search Algorithm
Saurya Das, Randy Kobes, G. Kunstatter · arXiv (Cornell University) · 2002
We show that it is possible to perform the adiabatic quantum search for a marked item in an unstructured database of $N$ items considerably faster than previous limits of ${\\cal O}(\\sqrt{N})$ time steps. In general this requires supplying the system with a large amount of energy that is recovered at the end of the computation. For example, if the lowest eigenvalue of the corresponding time dependent Hamiltonian achieves a maximum $\\propto\\sqrt{N}$, then for large $N$ the time required for the search approaches a constant, independent of $N$.