ملتقى الفيزيائيين العرب > منتديات أقسام الفيزياء > منتدى فيزياء الـكـــــم. | ||
spin observable |
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To visualize some aspects of the canonical classical extension of quantum mechanics, consider the description of the spin-;. The convex set SQ can be viewed as a unit sphere in three dimensions (see, e.g., [20]): any two diametrically opposed points on the surface represent the ‘up’ and ‘down‘ polarization (pure) states along some direction in ordinary space. The non-unique decomposability of non-pure states into pure states is geometrically apparent: for instance, the mixture with equal weights of the ‘spin-up’ and ‘spin-down’ states along a given axis represents the unpolarized state, but the choice of the axis is completely arbitrary, so that the (degenerate) density operator of the unpolarized state admits infinitely many convex decompositions into pure states. |
الذين يشاهدون محتوى الموضوع الآن : 1 ( الأعضاء 0 والزوار 1) | |
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