English

Quantum state discrimination in a $\mathcal{PT}$-symmetric system of a single trapped ion

Quantum Physics 2025-03-03 v1 Atomic Physics

Abstract

We experimentally demonstrate an unambiguous quantum state discrimination of two qubit states under a non-Hermitian Hamiltonian with parity-time-reversal (PT\mathcal{PT}) symmetry in a single trapped 40^{40}Ca+^+ ion. We show that any two non-orthogonal states can become orthogonal subjected to time evolution of a PT\mathcal{PT}-symmetric Hamiltonian in both the PT\mathcal{PT}-symmetry preserving and broken regimes, thus can be discriminated deterministically. For a given pair of candidate states, we show that the parameters of the Hamiltonian must be confined in a proper range, within which there exists an optimal choice to realize quantum brachistochrone for the fastest orthogonalization. Besides, we provide a clear geometric picture and some analytic results to understand the main conclusions. Our work shows a promising application of non-Hermitian physics in quantum information processing.

Keywords

Cite

@article{arxiv.2502.20717,
  title  = {Quantum state discrimination in a $\mathcal{PT}$-symmetric system of a single trapped ion},
  author = {Chenhao Zhu and Tingting Shi and Liangyu Ding and Zhiyue Zheng and Xiang Zhang and Wei Zhang},
  journal= {arXiv preprint arXiv:2502.20717},
  year   = {2025}
}

Comments

6 pages, 4 figures