English

Non-unitary extension of Grover's search algorithm

Quantum Physics 2026-04-28 v1 Mathematical Physics math.MP

Abstract

We have developed a non-unitary extension of Grover's search algorithm by changing the hidden geometry of Hilbert space carried by diffusion operator. Our algorithm finds the solution for search problem by performing a unique bigger rotation rather than small rotations in order polynomial times in the size NN of search space. We analyze the complexity of implementing the non-unitary operation and we observed that the price paid by performing this rotation is due the normalization. In Kraus operator approach we need O(N)O(N) repetition of the algorithm to have a chance of measuring a solution in a post-selection, this is no better than the classical solution. However, the quantum singular value transform in addition with block encoding and Chebyshev polynomial approximation, we got complexity O(N)O(\sqrt{N}) and reach the Grover's bound with an extra resource of one single qubit, compared with the standard Grover's algorithm.

Keywords

Cite

@article{arxiv.2604.23382,
  title  = {Non-unitary extension of Grover's search algorithm},
  author = {V. N. A. Lula-Rocha and M. A. S. Trindade},
  journal= {arXiv preprint arXiv:2604.23382},
  year   = {2026}
}