Consider a quantum system prepared in an input state. One wants to drive it into a target state. Assuming classical states and operations as free resources, I identify a geometric cost function which quantifies the difficulty of the protocol in terms of how different it is from a classical process. The quantity determines a lower bound to the number of commuting unitary transformations required to complete the task. I then discuss the link between the quantum character of a state preparation and the amount of coherence and quantum correlations that are created in the target state.
How Difficult is it to Prepare a Quantum State? / Girolami, D.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 122:1(2019), p. 010505.
|Titolo:||How Difficult is it to Prepare a Quantum State?|
|Data di pubblicazione:||2019|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1103/PhysRevLett.122.010505|
|Appare nelle tipologie:||1.1 Articolo in rivista|