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arXiv · 2308.03605

Quadratic acceleration of multi-step probabilistic algorithms for state preparation

Hirofumi Nishi·Taichi Kosugi·Yusuke Nishiya·Yu-ichiro Matsushita
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Abstract

For quantum state preparation, a non-unitary operator is typically designed to decay undesirable states contained in an initial state using ancilla qubits and a probabilistic action. Probabilistic algorithms do not accelerate the computational process compared to classical ones. In this study, quantum amplitude amplification (QAA) and multi-step probabilistic algorithms are combined to achieve quadratic acceleration. This method outperforms quantum phase estimation in terms of infidelity. The quadratic acceleration was confirmed by the probabilistic imaginary-time evolution (PITE) method.

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Hirofumi Nishi, Taichi Kosugi, Yusuke Nishiya, Yu-ichiro Matsushita. 2023-08-07. Quadratic acceleration of multi-step probabilistic algorithms for state preparation. https://arxiv.org/abs/2308.03605

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