Topological Uhlmann phase transitions for a spin- j particle in a magnetic field

  title={Topological Uhlmann phase transitions for a spin-
 particle in a magnetic field},
  author={D. Morachis Galindo and Fernando Rojas and Jes{\'u}s A. Maytorena},
The generalization of the geometric phase to the realm of mixed states is known as Uhlmann phase. Recently, applications of this concept to the field of topological insulators have been made and an experimental observation of a characteristic critical temperature at which the topological Uhlmann phase disappears has also been reported. Surprisingly, to our knowledge, the Uhlmann phase of such a paradigmatic system as the spin-j particle in presence of a slowly rotating magnetic field has not… 
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