Pure to mixed
|Converts a state vector or density matrix representation of a state to a density matrix|
|Other toolboxes required||none|
|Function category||Helper functions|
|This is a helper function that only exists to aid other functions in QETLAB. If you are an end-user of QETLAB, you likely will never have a reason to use this function.|
pure_to_mixed is a function that convert's a state's current representation (either as a pure state vector or as a density matrix) into a density matrix. This function just exists to make the code within some other functions a bit cleaner.
- RHO = pure_to_mixed(PHI)
- PHI: A density matrix or a pure state vector.
The following code shows that if v is a pure state vector then pure_to_mixed(v) == v*v', yet if rho is a density matrix then pure_to_mixed(rho) == rho.
>> v = RandomStateVector(2) v = 0.6732 - 0.5736i 0.3190 + 0.3407i >> pure_to_mixed(v) ans = 0.7822 0.0193 - 0.4123i 0.0193 + 0.4123i 0.2178 >> pure_to_mixed(v*v') ans = 0.7822 0.0193 - 0.4123i 0.0193 + 0.4123i 0.2178 >> v*v' ans = 0.7822 0.0193 - 0.4123i 0.0193 + 0.4123i 0.2178
Click here to view this function's source code on github.