A general framework for recursive decompositions of unitary quantum evolutions

作者:Dagli Mehmet*; D'Alessandro Domenico; Smith Jonathan D H
来源:Journal of Physics A-Mathematical and Theoretical, 2008, 41(15): 155302.
DOI:10.1088/1751-8113/41/15/155302

摘要

Decompositions of the unitary group U( n) are useful tools in quantum information theory as they allow one to decompose unitary evolutions into local evolutions and evolutions causing entanglement. Several recursive decompositions have been proposed in the literature to express unitary operators as products of simple operators with properties relevant in entanglement dynamics. In this paper, using the concept of grading of a Lie algebra, we cast these decompositions in a unifying scheme and show how new recursive decompositions can be obtained. In particular, we propose a new recursive decomposition of the unitary operator on N qubits, and give a numerical example.

  • 出版日期2008-4-18