Mixed quantum states with variable Planck constant

作者：de Gosson Maurice A^*

来源：Physics Letters, Section A: General, Atomic and Solid State Physics , 2017, 381(36): 3033-3037.

DOI：10.1016/j.physleta.2017.07.035

• Density operator
• Mixed states
• Variable Planck constant

Recent cosmological measurements tend to confirm that the fine structure constant a is not immutable and has undergone a tiny variation since the Big Bang. Choosing adequate units, this could also reflect a variation of Planck's constant h. The aim of this Letter is to explore some consequences of such a possible change of h for the pure and mixed states of quantum mechanics. Surprisingly enough it is found that not only is the purity of a state extremely sensitive to such changes, but that quantum states can evolve into classical states, and vice versa. A complete classification of such transitions is however not possible for the moment being because of yet unsolved mathematical difficulties related to the study of positivity properties of trace class operators.

• 出版日期2017-9-25