1. Quantum II (PHYS 4410) Lecture 4 Spin ½ continued. HWK 1 is due online at D2L by 5PM tomorrow. HWK 2 is due Wed. next week.

2. Physics Colloquium 4PM Today: Duane G1B20 Prof. Harry Nelson. Univ. of Calif. Santa Barbara “Light from Dark”

4. Consider three functions f(x), g(y), and h(z) which obey the equation: f(x) + g(y) + h(z) = C = constant. How many of the functions must be constant? A) f, g, and h must all be constants. B) One of f, g, and h, must be a constant. C) Two of f, g, and h must be constants. 81 If H is a sum,  is a product.

5. You have two spins, so you create a new hermitian operator: Therefore, you expect that the eigen vectors of this hermitian operator are: A)A sum of the electron and proton eigen vectors. B)A product of the ele. and prot. Eigen vectors. C)Something else

6. You have two spin ½ objects and consider the sum of their z-components of spin: What is the maximum value you expect for the quantum number m total A)½ B)0 C)1 D)2 E)Something else.

8. 150 Suppose we represent a qubit so that: What is the appropriate matrix operator for NOT? A) B) C) D) E) None of these and

9. 150 Given a qubit in a superposition state: What is the effect of operating with NOT? A) B) C) D) E) None of these What about (NOT) (NOT) ?