Pure to mixed
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| 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.
Syntax
- RHO = pure_to_mixed(PHI)
Argument descriptions
- PHI: A density matrix or a pure state vector.
Examples
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 0.2178Source code
Click here to view this function's source code on github.