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arXiv · 2008.08682

Beyond Density Matrices: Geometric Quantum States

Fabio Anza·James P. Crutchfield
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Abstract

A quantum system's state is identified with a density matrix. Though their probabilistic interpretation is rooted in ensemble theory, density matrices embody a known shortcoming. They do not completely express an ensemble's physical realization. Conveniently, when working only with the statistical outcomes of projective and positive operator-valued measurements this is not a hindrance. To track ensemble realizations and so remove the shortcoming, we explore geometric quantum states and explain their physical significance. We emphasize two main consequences: one in quantum state manipulation and one in quantum thermodynamics.

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Fabio Anza, James P. Crutchfield. 2020-08-19. Beyond Density Matrices: Geometric Quantum States. https://doi.org/10.1103/physreva.103.062218

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