Information geometry and entanglement under phase-space deformation through nonsymplectic congruence transformation

Abstract:The Fisher-Rao (FR) information matrix is a central object in multiparameter quantum estimation theory. The geometry of a quantum state can be envisaged through the Riemannian manifold generated by the FR-metric corresponding to the quantum state. Interestingly, any congruence transformation $GL(2n,\mathbb{R})$ in phase space leaves the FR-distance for Gaussian states invariant. In the present paper, we investigate whether this isometry affects the entanglement in the bipartite system. It turns out that the entanglement-generating congruent transformation depends upon the system and the symplectic structure of phase-space. To make our study relevant to physical systems, we choose Bopp's shift in phase space as an example of $GL(2n,\mathbb{R})$, so that the results can be interpreted in terms of noncommutative (NC) phase-space deformation. We provide a quantitative estimation for the dependence of symplectic eigenvalues on the deformation parameters and explain the induced entanglement through phase-space deformation. The coexistence of FR-isometry with deformation-dependent entanglement demonstrates that statistical distinguishability and quantum correlations constitute complementary aspects of the geometry of Gaussian quantum systems. With the help of toy models of oscillators in NC-space, we illustrate our results quantitatively.

arXiv:2505.02269 [quant-ph]

(or arXiv:2505.02269v4 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2505.02269 Focus to learn more arXiv-issued DOI via DataCite

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