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Main Authors: Wu, Ya-Dong, Zhu, Yan, Chiribella, Giulio, Liu, Nana
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2303.05097
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author Wu, Ya-Dong
Zhu, Yan
Chiribella, Giulio
Liu, Nana
author_facet Wu, Ya-Dong
Zhu, Yan
Chiribella, Giulio
Liu, Nana
contents The characterization of continuous-variable quantum states is crucial for applications in quantum communication, sensing, simulation and computing. However, a full characterization of multimode quantum states requires a number of experiments that grows exponentially with the number of modes. Here we propose an alternative approach where the goal is not to reconstruct the full quantum state, but rather to estimate its characteristic function at a given set of points. For multimode states with reflection symmetry, we show that the characteristic function at M points can be estimated using only O(log M ) copies of the state, independently of the number of modes. When the characteristic function is known to be positive, as in the case of squeezed vacuum states, the estimation is achieved by an experimentally friendly setup using only beamsplitters and homodyne measurements.
format Preprint
id arxiv_https___arxiv_org_abs_2303_05097
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Efficient Learning of Continuous-Variable Quantum States
Wu, Ya-Dong
Zhu, Yan
Chiribella, Giulio
Liu, Nana
Quantum Physics
The characterization of continuous-variable quantum states is crucial for applications in quantum communication, sensing, simulation and computing. However, a full characterization of multimode quantum states requires a number of experiments that grows exponentially with the number of modes. Here we propose an alternative approach where the goal is not to reconstruct the full quantum state, but rather to estimate its characteristic function at a given set of points. For multimode states with reflection symmetry, we show that the characteristic function at M points can be estimated using only O(log M ) copies of the state, independently of the number of modes. When the characteristic function is known to be positive, as in the case of squeezed vacuum states, the estimation is achieved by an experimentally friendly setup using only beamsplitters and homodyne measurements.
title Efficient Learning of Continuous-Variable Quantum States
topic Quantum Physics
url https://arxiv.org/abs/2303.05097