Rethinking Collapse: Coupling Quantum States to Classical Bits with quasi-probabilities

• URL: http://arxiv.org/abs/2512.03929v1
• Date: Wed, 03 Dec 2025 16:28:45 GMT
• Title: Rethinking Collapse: Coupling Quantum States to Classical Bits with quasi-probabilities
• Authors: Dagomir Kaszlikowski, Pawel Kurzynski,
• Abstract summary: We propose a formulation of quantum measurement within a modified framework of frames.<n>A quantum system - a single qubit - is directly coupled to a classical measurement bit.<n>We capture the nonclassical nature of measurement through the quasi-bistochastic structure of the interaction.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We propose a formulation of quantum measurement within a modified framework of frames, in which a quantum system - a single qubit - is directly coupled to a classical measurement bit. The qubit is represented as a positive probability distribution over two classical bits, a and a', denoted by p(aa'). The measurement apparatus is described by a classical bit $α= \pm 1$, initialized in the pure distribution $p(α) = \frac{1}{2}(1 + α)$. The measurement interaction is modeled by a quasi-bistochastic process $ S(bb'β\mid aa'α)$ - a bistochastic map that may include negative transition probabilities, while acting on an entirely positive state space. When this process acts on the joint initial state $p(aa')p(α)$, it produces a collapsed state $p(bb'\midβ)$, yielding the measurement outcome $β$ with the correct quantum-mechanical probability $p(β)$. This approach bypasses the von Neumann chain of infinite couplings by treating the measurement register classically, while capturing the nonclassical nature of measurement through the quasi-bistochastic structure of the interaction.

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