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Main Author: Peng, Xiao-Fu
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2506.14458
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author Peng, Xiao-Fu
author_facet Peng, Xiao-Fu
contents In this paper, we define a universal measure of macroscopicity $β$ in the form of, ({\em experimentally observed coherence time})/({\em characteristic time required to repeatably distinguish the components of a quantum superposition state}), to divide the quantum/classical (Q-C) boundary. The analysis shows that, for a matter-wave interferometer, covering systems from electron to macromolecular, the measure of its macroscopicity is expressed by $β=pθd/8\hbar$, and it consistently yields $β<1$ by investigating the coherence data reported in the literature. The result implies that limited advancement has been made toward exploring the Q-C boundary in such experiments. Additionally, for a Ramsey-like interferometer, the measure of its macroscopicity is expressed as $β=8π^3αν_0r_s^2ν_s^2T/ (9c^2)$. After analyzing the reported experimental data, we find that a maximum value of $β\sim 300$ is achieved in the vertical atomic fountain experiments. Therefore, searching the Q-C boundary in the atomic fountain may be a more proper direction.
format Preprint
id arxiv_https___arxiv_org_abs_2506_14458
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Macroscopicity of quantum superposition
Peng, Xiao-Fu
Quantum Physics
In this paper, we define a universal measure of macroscopicity $β$ in the form of, ({\em experimentally observed coherence time})/({\em characteristic time required to repeatably distinguish the components of a quantum superposition state}), to divide the quantum/classical (Q-C) boundary. The analysis shows that, for a matter-wave interferometer, covering systems from electron to macromolecular, the measure of its macroscopicity is expressed by $β=pθd/8\hbar$, and it consistently yields $β<1$ by investigating the coherence data reported in the literature. The result implies that limited advancement has been made toward exploring the Q-C boundary in such experiments. Additionally, for a Ramsey-like interferometer, the measure of its macroscopicity is expressed as $β=8π^3αν_0r_s^2ν_s^2T/ (9c^2)$. After analyzing the reported experimental data, we find that a maximum value of $β\sim 300$ is achieved in the vertical atomic fountain experiments. Therefore, searching the Q-C boundary in the atomic fountain may be a more proper direction.
title Macroscopicity of quantum superposition
topic Quantum Physics
url https://arxiv.org/abs/2506.14458