Please Compute Concurrence Whats wrong

[coffekreizy]

Please Compute Concurrence...Whats wrong!

I have this rho matrix:

rho=[0.001 0 0 0.125;0 0.499 -0.374 0;0 -0.374 0.499 0;0.125 0 0 0.001];


Why the concurrence is different if you compute numerically (you can download programs for compute the concurrence in this sites:
http://optics.szfki.kfki.hu/~toth/qubit4matlab.html
http://www.dr-qubit.org/matlab.php

And if you use the Ec. 26 of Eberly paper/ Optics comm 264 (2006) 393-397

 

[haushofer]

I'm afraid you'll have to put a little more effort in your post if you expect people to help you.

 

[Entropia]

Thank you for sharing this information. I understand the importance of accurate and consistent results in research. After looking into the provided information, it seems that there could be multiple reasons for the differences in the calculated concurrence values.

Firstly, it is important to note that the calculation of concurrence involves complex mathematical equations and can be affected by various factors such as numerical errors and rounding. Therefore, it is possible that the different programs or methods used for computation may lead to slightly different results.

Additionally, the concurrence calculation involves the determination of eigenvalues and eigenvectors of the density matrix, which can be affected by the initial input values. In this case, the input values for the density matrix may have been slightly different, leading to variations in the calculated concurrence.

Moreover, it is also possible that the programs or methods used for computation may have different algorithms or approximations, which can also contribute to the differences in the results.

In order to determine the exact reason for the discrepancies, further investigation and analysis would be required. I would suggest carefully reviewing the methods and algorithms used in each program and comparing the results with other established methods to ensure accuracy and consistency in the calculations.