A NEW METHOD TO CALCULATE THE INCONCLUSIVE COEFFICIENTS IN THE QUANTUM STATE DISCRIMINATION

摘要

The problem of determining the state of a quantum system is a central task in any quantumninformation processing. However, there are limitations imposed by quantum mechanics on thenpossibilities to determine the state of a quantum system. For example, nonorthogonal statesncannot be discriminated perfectly. In this paper, we propose a new method to calculate theninconclusive coe±cients based on the solution of a quadratic system, replacing the determinationnof the roots of a polynomial of degree 8, used in an algorithm to quantum state discriminationnpreviously de¯ned in the literature. The new method simpli¯es the calculation ofnthe inconclusive coe±cients and can be extended very easily to any dimension. The method wasnwritten in Matlab and successfully applied to problems with di®erent dimensions.