The dispersion relation for phonons in a one-dimensional lattice is ω = ±√(4K/M) |sin(πk/2)|. What is the maximum frequency?
Q1. The dispersion relation for phonons in a one-dimensional lattice is ω = ±√(4K/M) |sin(πk/2)|. What is the maximum frequency?
Answer: √(4K/M)
Explanation: Maximum frequency occurs when sin(πk/2) = 1, so ω_max = √(4K/M).