U(x)= = Σ v(x- v(xna) (n+a U(x) 4 x -3a/2 -a/2 0 a/2 3a/2 -a/2 v(x)4 ト (x)4 x a/2 -a/2 a/2 (a) (b) (x) = eix + re-ikx, x s VI = teikx x * > 199 - a 2' 4,(x) = teikx, a 312 2' = e-ikx + reikx, x >> 2 (x) = A₁(x) + By,(x), <x 02 2' 02 VI \'(x + a) = eika\'(x) '(x + a) = eika\'(x)_ cos ka 12 - 2 2t 1 eika + 2t 3 h²K² 2m 1 = |1|2 + |r|² ΑΣ Φί + εφι Φίλ 2m 2m i = 1, 2. (01.02) = 01'(x)2(x) — 1(x)2'(x) - r = tired cos (Ka + 8) h²K² = cos ka, 8 = t 2m Κα + δ = ηπ &gap 2πn h² ma .2 || 1 0 K Omax – Omin = 0(||) h²K |t|= cos == d cot & = mg