Computing the distance between quantum channels: usefulness of the Fano representation

Giuliano Benenti (1, 2) , Giuliano Strini (3)

1 CNR-INFM, and Center for Nonlinear and Complex Systems
2 INFN - Istituto Nazionale di Fisica Nucleare, Sezione di Milano
3 Dipartimento di Fisica

The diamond norm measures the distance between two quantum channels. From an operational vewpoint, this norm measures how well we can distinguish between two channels by applying them to input states of arbitrarily large dimensions. In this paper, we show that the diamond norm can be conveniently and in a physically transparent way computed by means of a Monte-Carlo algorithm based on the Fano representation of quantum states and quantum operations. The effectiveness of this algorithm is illustrated for several single-qubit quantum channels.

Mots clés: Physical Sciences

Giuliano Benenti, Giuliano Strini. Computing the distance between quantum channels: usefulness of the Fano representation. Journal of Physics B: Atomic, Molecular and Optical Physics, 2010, 43 (21), pp.215508. ⟨10.1088/0953-4075/43/21/215508⟩. ⟨hal-00569863⟩