Thermodynamics, Statistical Physics, and Quantum Mechanics

THERMODYNAMICS AND STATISTICAL PHYSICS 223

as found in (S.4.96.6). The mean square noise voltage is

b)If then (S.4.96.6) becomes

Applications to Solid State

Thermal Expansion and Heat Capacity

(Princeton)

4.97

a) First solution: We can calculate the average displacement of an oscillator:

Since the anharmonic term is small, we can expand the
exponent in the integral: