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--- density-matrix [June 09, 2026 at 13:41] – Ivan Janevski
+++ density-matrix [June 13, 2026 at 03:13] (current) – external edit 127.0.0.1
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 **Density matrix** (written as $\rho$) is a matrix representation of a quantum state.
-It's a more general way to represent a quantum state compared to the [[state vector|state-vector]] $\lvert\psi\rangle$. While a state vector can only represent [[pure-state|pure states]], a density matrix can represent [[mixed-state|mixed states]] as well, making it the correct tool for open quantum systems, noisy circuits, and statistical ensembles of quantum states.
+It's a more general way to represent a quantum state compared to the [[state-vector|state vector]] $\lvert\psi\rangle$. While a state vector can only represent [[pure-state|pure states]], a density matrix can represent [[mixed-state|mixed states]] as well, making it the correct tool for open quantum systems, noisy circuits, and statistical ensembles of quantum states.
 Every pure state $\lvert\psi\rangle$ has a corresponding density matrix constructed by the outer product of the ket with its bra.
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 ## Time evolution
-Under Hamiltonian evolution, the density matrix evolves according to the von Neumann equation $d\rho/dt = -i[H,\rho]/\hbar$. For open systems with environmental noise, this generalizes to the [[lindbald-equation|Lindblad master equation]], which adds dissipative terms describing decoherence and relaxation.
+Under Hamiltonian evolution, the density matrix evolves according to the von Neumann equation $d\rho/dt = -i[H,\rho]/\hbar$. For open systems with environmental noise, this generalizes to the [[lindblad-equation|Lindblad master equation]], which adds dissipative terms describing decoherence and relaxation.