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arXiv · 2401.10602

Fractional Conformal Map, Qubit Dynamics and the Leggett-Garg Inequality

Sourav Paul·Anant Vijay Varma·Sourin Das
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Abstract

Any pure state of a qubit can be geometrically represented as a point on the extended complex plane through stereographic projection. By employing successive conformal maps on the extended complex plane, we can generate an effective discrete-time evolution of the pure states of the qubit. This work focuses on a subset of analytic maps known as fractional linear conformal maps. We show that these maps serve as a unifying framework for a diverse range of quantum-inspired conceivable dynamics, including (i) unitary dynamics,(ii) non-unitary but linear dynamics and (iii) non-unitary and non-linear dynamics where linearity (non-linearity) refers to the action of the discrete time evolution operator on the Hilbert space. We provide a characterization of these maps in terms of Leggett-Garg Inequality complemented with No-signaling in Time (NSIT) and Arrow of Time (AoT) conditions.

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Sourav Paul, Anant Vijay Varma, Sourin Das. 2024-01-19. Fractional Conformal Map, Qubit Dynamics and the Leggett-Garg Inequality. https://doi.org/10.1088/1751-8121%2Fad742a

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