2
$\begingroup$

If we have one density matrix

$$\rho=\begin{bmatrix}1/2&&1/2\\1/2&&1/2\end{bmatrix}$$

for the state $\lvert\psi\rangle=\frac{1}{\sqrt2}(\lvert g\rangle+\lvert e\rangle)$

and a different one

$$\rho=\begin{bmatrix}1/2&&i/2\\-i/2&&1/2\end{bmatrix}$$

for the state $\lvert\psi\rangle=\frac{1}{\sqrt2}(i\lvert g\rangle+\lvert e\rangle)$

What are the differences between these two states? Is there some physical meaning?

$\endgroup$
  • $\begingroup$ Have you tried to compare the norms of these states? $\endgroup$ – Ice-Nine Feb 6 '18 at 13:10
  • $\begingroup$ @Ice-Nine they are both 1 right? $\endgroup$ – James Feb 6 '18 at 13:41
  • $\begingroup$ suggest you change title to "difference between complex and real coherences". "imaginary" could imply you're imagining things. $\endgroup$ – ZeroTheHero Feb 6 '18 at 13:47
  • $\begingroup$ What is the effect of the complex rather than real phase difference? $\endgroup$ – ZeroTheHero Feb 6 '18 at 13:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.