Fund Quantum Mechanics Lect & HW Solutions 90

Fund Quantum Mechanics Lect & HW Solutions 90 - 72...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
72 CHAPTER 5. MULTIPLE-PARTICLE SYSTEMS 5.6.1 Solution ident-a Question: Check that indeed any linear combination of the triplet states is unchanged under particle exchange. Answer: In the notations of the previous section, the most general linear combination of the triplet states takes the form: a 1 | 1 1 a + a 2 | 1 0 a + a 3 | 1 1 a or writing out their deFnitions as found there, a 1 ↑↑ + a 2 1 2 ( ↑↓ + ↓↑ ) + a 3 ↓↓ . Exchanging the two particles involved means to interchange the order of each pair of arrows, since by deFnition the Frst arrow refers to particle 1 and the second to particle 2. A look at the expression above shows that such an interchange of order does absolutely nothing to these states. 5.6.2 Solution ident-b Question: Suppose the electrons of the hydrogen molecule are in the excited antisymmetric spatial state a [ ψ l ( vr 1 ) ψ r ( vr 2 ) ψ r ( vr 1 ) ψ l ( vr 2 )] . In that case what can you say about the spin state?
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.
Ask a homework question - tutors are online