Comments on: Decomposition in unitary matrices http://jice.lavocat.name/blog/2009/07/decomposition-in-unitary-matrices/ Mon Bioblog (humeurs, tendances et aventures en tout genres) Tue, 10 Jan 2012 16:12:48 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Jice http://jice.lavocat.name/blog/2009/07/decomposition-in-unitary-matrices/comment-page-1/#comment-155 Jice Wed, 08 Jul 2009 17:19:54 +0000 http://jice.lavocat.name/blog/?p=615#comment-155 <p>Do you mean the following matrix :</p> <p> </p> <p>$$ \begin{pmatrix} 1 & & \\ & 0 & \\ & & I \end{pmatrix} = \begin{pmatrix} e^{i\pi/3} & & \\ & e^{2i\pi/3} & \\ & & e^{i\pi/3}I \end{pmatrix}+\begin{pmatrix} e^{-i\pi/3} & & \\ & e^{-2i\pi/3} & \\ & & e^{-i\pi/3}I \end{pmatrix}$$</p> Do you mean the following matrix :

 

\begin{pmatrix}<br /> 1 & & \\<br /> & 0 & \\<br /> & & I<br /> \end{pmatrix} =<br /> \begin{pmatrix}<br /> e^{i\pi/3} & & \\<br /> & e^{2i\pi/3} & \\<br /> & & e^{i\pi/3}I<br /> \end{pmatrix}+\begin{pmatrix}<br /> e^{-i\pi/3} & & \\<br /> & e^{-2i\pi/3} & \\<br /> & & e^{-i\pi/3}I<br /> \end{pmatrix}

]]> By: Jon http://jice.lavocat.name/blog/2009/07/decomposition-in-unitary-matrices/comment-page-1/#comment-148 Jon Wed, 08 Jul 2009 10:27:22 +0000 http://jice.lavocat.name/blog/?p=615#comment-148 Hi J.C. Certainly the matrix 10I (I being the identity matrix) is not a sum of two unitaries. Hi J.C. Certainly the matrix 10I (I being the identity matrix) is not a sum of two unitaries.

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