Chapter 6: Coherent and Mixed States Flashcards
1
Q
Coherent State
A
- Eigenstate of annihilation operator
- Existence surprising, because a is not Hermiatian
- Coherent state not orthogonal in general
- Creation operator has no (right) eigenstate
2
Q
Coherent State
(Arbitrary State)
A
3
Q
Coherent State
(Photon)
A
a(†) (creates) destroys photon in mode kz
4
Q
Mixed State
A
- Consider: System is prepared in state | ψi > with probability pi
- Let ρ be density matrix
- Expectation values give by trace of product of density matrix and operator
5
Q
Density Matrix
(Properties)
A
- Probability is conserved
- Self-adjoint
- Projector
6
Q
Pure vs Mixed State
A
7
Q
Density Matrix
(Time Evolution)
A
Schrödinger equation for mixed stat
