Tagged Questions

To be used for linear algebra, and closely related disciplines such as tensor algebras and maybe clifford algebras.

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Definition of the “support” of the reduced density matrix

Some of the papers in condensed matter physics use the word "support" (space). For example, the following papers use the support especially for the reduced density matrix. http://journals.aps.org/prb/...
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What's the proof that sum of all projection operators for orthonormal basis gives us identity operator? [closed]

\begin{align} \ I = \begin{bmatrix}1 & 0\\0 & 1\end{bmatrix} \end{align} \begin{align} \ {\sum_{i} |i{\rangle}}{{\langle}i|}=I \end{align} $I$ is identity operator, while the $|i{\rangle}$ ...
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Expressing operator in bra-ket notation, knowing just matrix elements

This is in context of unitary transformations between two othonormal bases $\{ | e_i \rangle\}$ and $\{ | \bar{e}_i \rangle\}$. I define $U$ by $$U| e_i \rangle = | \bar{e}_i \rangle$$ Now I can ...
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Importance of Kronecker product in quantum computation

To get product state of two states $|\phi \rangle$ and $|\psi \rangle$, we use Kronecker product $|\phi \rangle \otimes |\psi \rangle$. Instead of Kronecker product $\otimes$, can we use Cartesian ...