= Lindblad operator
{c}
A Lindblad operator describes one dissipative contribution to a Markovian master equation for a <density operator>. In the common convention,
$$
\dot\rho=-i[H,\rho]+\sum_\alpha\left(L_\alpha\rho L_\alpha^\dagger-\frac12\{L_\alpha^\dagger L_\alpha,\rho\}\right),
$$
with $\hbar=1$. Absorbing a rate into $L_\alpha$ gives it square-root-rate units.
For a two-level system, $L=\sqrt\gamma\,|0\rangle\langle1|$ models decay from the excited state, while a diagonal operator can describe <dephasing>. The gain and anticommutator terms together preserve trace; retaining only the first would not define the same unconditional evolution. The operators are not unique, and a stochastic jump interpretation needs a specified monitoring of the environment. The physical object is the complete <Lindbladian>, including its Hamiltonian and dissipative parts.
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