Beyond density matrices: Geometric quantum states
نویسندگان
چکیده
In quantum mechanics, states are described by density matrices. Though their probabilistic interpretation is rooted in ensemble theory, matrices embody a known shortcoming. They do not completely express the physical realization of an ensemble. Conveniently, outcome statistics projective and positive operator-valued measurements depend on realization, only matrix. Here, we show how geometric approach to mechanics tracks realizations. We so two concrete cases finite-dimensional system interacting with another one (i) Hilbert space, relevant for thermodynamics, (ii) infinite-dimensional state-manipulation protocols.
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ژورنال
عنوان ژورنال: Physical review
سال: 2021
ISSN: ['0556-2813', '1538-4497', '1089-490X']
DOI: https://doi.org/10.1103/physreva.103.062218