Evolution speed of open quantum dynamics
Abstract
The space of density matrices is embedded in a Euclidean space to deduce the dynamical equation satisfied by the state of an open quantum system. The Euclidean norm is used to obtain an explicit expression for the speed of the evolution of the state. The unitary contribution to the evolution speed is given by the modified skew information of the Hamiltonian, while the radial component of the evolution speed, connected to the rate at which the purity of the state changes, is shown to be determined by the modified skew information of the Lindblad operators. An opensystem analog of the quantum navigation problem is posed, and a perturbative analysis is presented to identify the amount of change on the speed. Properties of the evolution speed are examined further through example systems, showing that the evolution speed need not be a decreasing function of time.
 Publication:

Physical Review Research
 Pub Date:
 November 2019
 DOI:
 10.1103/PhysRevResearch.1.033127
 arXiv:
 arXiv:1906.04766
 Bibcode:
 2019PhRvR...1c3127B
 Keywords:

 Quantum Physics;
 Mathematical Physics
 EPrint:
 5 pages