English

On the fidelity of two pure states

Quantum Physics 2009-11-06 v1

Abstract

The fidelity of two pure states (also known as transition probability) is a symmetric function of two operators, and well-founded operationally as an event probability in a certain preparation-test pair. Motivated by the idea that the fidelity is the continuous quantum extension of the combinatorial equality function, we enquire whether there exists a symmetric operational way of obtaining the fidelity. It is shown that this is impossible. Finally, we discuss the optimal universal approximation by a quantum operation.

Keywords

Cite

@article{arxiv.quant-ph/0011053,
  title  = {On the fidelity of two pure states},
  author = {Andreas Winter},
  journal= {arXiv preprint arXiv:quant-ph/0011053},
  year   = {2009}
}

Comments

LaTeX2e, 8 pages, submitted to J. Phys. A: Math. and Gen