Discrete Quantum Processes

Understand

A discrete quantum process is defined as a sequence of local states $\rho_t$, $t=0,1,2,...$, satisfying certain conditions on an $L_2$ Hilbert space $H$.

• If $\rho =\lim\rho_t$ exists, then $\rho$ is called a global state for the system.
• In important cases, the global state does not exist and we must then work with the local states.
• In a natural way, the local states generate a sequence of quantum measures which in turn define a single quantum measure $\mu$ on the algebra of cylinder sets $\cscript$.