English

Unitary Evolution Between Pure and Mixed States

Quantum Physics 2009-10-28 v4 General Relativity and Quantum Cosmology High Energy Physics - Theory

Abstract

We propose an extended quantum mechanical formalism that is based on a wave operator \vr\vr, which is related to the ordinary density matrix via ρ=\vr\vr\rho=\vr\vr^\dagger. This formalism allows a (generalized) unitary evolution between pure and mixed states. It also preserves much of the connection between symmetries and conservation laws. The new formalism is illustrated for the case of a two level system.

Keywords

Cite

@article{arxiv.quant-ph/9504019,
  title  = {Unitary Evolution Between Pure and Mixed States},
  author = {B. Reznik},
  journal= {arXiv preprint arXiv:quant-ph/9504019},
  year   = {2009}
}

Comments

13 pages, latex. Revised version. To appear in Phys. Rev. Lett