118

Click here to load reader

第二章 波函数 和 Schrodinger 方程

  • Upload
    edita

  • View
    168

  • Download
    17

Embed Size (px)

DESCRIPTION

第二章 波函数 和 Schrodinger 方程. §1 波函数的统计解释 §2 态叠加原理 §3 力学量的平均值和算符的引进 §4 Schrodinger 方程 §5 粒子流密度和粒子数守恒定律 §6 定态 Schrodinger 方程. §1 波函数的统计解释. (一)波函数 (二)波函数的解释 (三)波函数的性质. 描写自由粒子的平 面 波. (一)波函数. 称为 de Broglie 波。此式称为自由粒子的波函数。. - PowerPoint PPT Presentation

Citation preview

  • Schrodinger 1 2 3 4 Schrodinger 5 6 Schrodinger

  • 1

  • 3 deBroglie (1) (2) (3)

  • 1. O

  • 2. 1

  • 1.;2. .

  • r r Born

  • (r) Born (r) |(r)|2 | (r)|2 r | (r)|2 x y z r xyz

  • trd=dxdydz(r,t)d W( r, t) = C| (r,t)|2 dC1tr w( r, t ) = {dW(r, t )/ d} = C | (r,t)|2 V t W(t) = V dW = Vw( r, t ) d= CV | (r,t)|2 d

  • 2 C | (r , t)|2 d= 1, C C = 1/ | (r , t)|2 d | (r , t)|2 d , C 0,

  • 3 2 4 (r , t ) C (r , t ) C t r1 r2 (r, t) C (r, t) (r , t ) C (r , t )

  • (r , t ) | (r , t )|2 d= A A |(A)-1/2 (r , t )|2 d= 1 (A)-1/2 (r , t ) (r , t )(A)-1/2 (r , t ) exp{i} (r , t )

  • 4I Dirac x=x0 fx Fourier k=px/, dk= dpx/,

  • II t=0 A12 2 = 1 A1= [2]-1/2,

  • 2

  • = C11 + C22 ||2 = |C11+ C22|2 = (C1*1*+ C2*2*) (C11+ C22) = |C1 1|2+ |C22|2 + [C1*C21*2 + C1C2*12*] 1 2

  • 1 2 ,..., n ,... = C11 + C22 + ...+ Cnn + ... ( C1 , C2 ,...,Cn ,...) 12...n...12 = C11 + C22 .C1 C2

  • p deBroglie p p

  • (r,t) r C(p, t) p (r,t) p

  • (r,t) C(p, t)

  • 3 1 2 1 2 3 4Hamilton

  • :

  • 1 (x) | (x)|2 x(r) |(r)|2 r x2(x)

  • (x) c(px) (x)(x)px(x) px x px1

  • (r) *(r)(r),F

  • 23

  • 4Hamilton

  • 4 Schrodinger V(r) Schrodinger

  • 1926Schrodinger (1): (2)

  • t r p 1

  • 2 3 p, E1t = t0 ( r, t0) 21( r, t ) 2( r, t ) ( r, t)= C11( r, t ) + C22( r, t ) ,

  • E t

  • E = p2/2 43(1)(2)

  • V(r) Schrodinger V(r) 4

  • () Schrodinger N i (i = 1, 2,..., N) ( r1, r2, ..., rN ; t) i Ui(ri) V(r1, r2, ..., rN) Schrodinger

  • Hamilton Z Coulomb i Coulomb

  • 5

  • t r

  • Schrodinger

  • J(7) Eq.7 Eq.7 Gauss S

  • 1

  • 1. Born d W(r, t) = |(r, t)|2 d 2. (r, t) 3.Schrodinger1

  • S 2. :1. Born w(r, t) = *(r, t) (r, t)t r(r, t) r, t2

  • 3 I II I II Schrodinger

  • 6 Schrodinger

    Schrodinger Hamilton

  • Schrodinger Schrodinger V(r)t t, r

  • Schrodinger (r)t=0(r,0) t=2E/h de Broglie E (r,t)(r,t)

  • Hamilton1Hamilton (r, t)E(r, t) Schrodinger

  • 2 1 + 2 E H H

    3

  • ( r, t) E1 Schrodinger2 E 3 n En 4 Cn

  • 21

  • 1. 2. Schrodinger 3. ||2 t3tt

  • 2.2 2.12.3

  • Schrodinger 1 2 3 47 8 9

  • 7

  • V(x,y,z) = V1(x) + V2(y) + V3(z) S- (x,y,z) = X(x) Y(y) Z(z) E = Ex + Ey + EzS- V(x,y,z) Schrodinger

  • S 1S 2 3 4

  • 1 S V(x) I II III I(x),II(x) III (x)22

  • 3 (-a) = (a) = 02S-1 2x - C2=0

  • 2 x = -a I(-a) = II(-a) 0 = A cos(-a + ) A sin(-a + )= 0 1

  • (1)+(2)(2)-(1)

  • n

  • I n = m

  • I II m = 2 n m = 2n+1

  • = 0 4 A

  • S S [] S

  • 1

  • 2n = 0 , E = 0, = 0 n = k, k=1,2,...n

  • 4n*(x) = n(x)5

  • 2.3 2.4 2.8

  • 1 2 1 2 3 4 5 6 8

  • x = Asin( t + )1 F = - kxV0 = 0 V = 0

  • 2 Vx x = a V V0 x = a

  • (a, V0)

  • 1 2 3 4 5 6

  • 1 HamiltonSchrodinger x

  • 2 > 1

  • H() H() H()() 0() H() 2. H()

  • 3. k k

  • b0 k b1 k b0 0, b1=0. Heven(); b1 0, b0=0. Hodd(). bk+2(k+2)(k+1)- bk 2k + bk(-1) = 0 bk H = co Hodd + ce Heven = (co Hodd + ce Heven e) exp[-2/2]

  • 3(I)=0 exp[-2/2]|=0 = 1 Heven()|=0 = b0 Hodd()|=0 = 0 (II) H() exp[2] H() exp[2] H() x=0, x =0,

  • H() H() n bn 0, bn+2 = 0.

    )

  • 4 H() Hn() Hn() n 2nHn() = 2n+1

  • H0 = 1, H1=2 H2 = 2H1-2nH0 = 42-2 H0=1 H2=42-2 H4 = 164-482+12 H1=2 H3=83-12 H5=325-1603+120(x)

  • 5 ( ) exp[-2] =Hn n2n dnHn /dn = 2n n! (I)=x d= dx (II)Hn()

  • 63. E0={1/2} 01.Hn()(2)n n= n=2.nn exp[-2/2]n Hn() n

  • 4. w0() = |0()|2 = = N02 exp[-2] = 0 ||1 | x|< 1(|x| = 1)V(x)=(1/ 2)2 x2 = {1/2} = E0

  • n n [-a, a] 5.

  • 1 Hamilton 1.

  • 2

  • 3 N N n1, n2, n3 n1 , n2 n3 = N - n1 - n2N{n1 , n2, n3 }

    N= n1 + n2 + n3

    n1

    n2

    0

    0,

    1,

    ...,

    N

    N+1

    1

    0,

    1,

    ...,

    N-1

    N

    2

    0,

    1,

    ...,

    N-2

    N-1

    ...,

    ...,

    ...,

    ...,

    ...

    ...

    N

    0,

    1

    N ( N= n1 + n2 + n3 ), {n1 , n2, n3 }

    (1/2)(N+1)(N+2)

  • Schrodinger1 V(x)-q xx

  • 2 V(x)

  • 3Hamilton Hamilton

  • 4Schrodinger Schrodinger Schrodinger

  • 2.5

    3.83.93.12

  • 9

  • ( E x

  • 1E > V0 E > 0, E > V0, k1 > 0, k2 > 0. Schrodinger

  • 1,2,3 exp[-iEt/] xx x > a III C'=0 1. 2.

  • : I D = JD/JIII R = JR/JI x > a III x x < 0 I x D R3. 4.

  • J = Aexp[ik1x] * = A* exp[-ik1x]= Cexp[ik1x] = Aexp[-ik1x]

  • : D+R=1 x > a III

  • k2=ik3k3=[2(V0-E)/ ]1/2 k2 ik3 sin ik3a = i sinh k3a E < V0 D + k2=[2(E-V0)/ ]1/2 E < V0 k2 tunnel effect .2E < V0

  • 1k3a >> 14 k1 k3 E V0/2, D0 = 4

  • 1: E=1eV, V0 = 2eV, a = 2 10-8 cm = 2 D 0.51a=5 10-8cm = 5 D 0.024 p/e 1840 a = 2 D 2 10-38 Gamow 2:

  • 2 x1 x2V(x)

  • 1 2

  • 1( N H3 ) (NH3)N H NN N 1. R-ST-U E N2. NH32.3786 1010 Hz

  • 2 (b)