Save and load the current vector or density matrix

You can save the current state into a file with the command

msave file;

You can load the current state from a file with the command

mload file;

The matrix

$$\begin{pmatrix}c_{0~0}& c_{0~1}& &\ldots& &c_{0~2^n-1}\\ c_{1~0}&... ...& &\ldots& & \\ c_{2^n-1~0}&c_{2^n-1~1}&&\ldots& &c_{2^n-1~2^n-1} \end{pmatrix}$$ (7)

is saved as the text

( $c_{0~0}~~c_{0~1}~~\ldots~~c_{0~2^n-1}$)( $c_{1~0}~~\ldots~~$) ... ( $c_{2^n-1~0}~~c_{2^n-1~1}~~\ldots~~c_{2^n-1~2^n-1}$);