- #1
cscott
- 782
- 1
Homework Statement
How do I get the expectation value of operator [itex]\sigma[/itex] using density matrix [itex]\rho[/itex] in a trace: [itex]Tr\left(\sigma\rho\right)[/itex]I have [itex]\sigma[/itex] and [itex]\rho[/itex] in matrix form but how do I get a number out of the trace?