En el apéndice del artículo, el camino de la partícula proporciona materiales cortados: integrales del camino, un experimento de dos huecos en átomos de neón fríos, marcos de teletransportación de partículas y otras escenas de crueldad y naturaleza sexual.
En mi opinión, no puede haber otra forma de considerar el formalismo matemático como lógicamente coherente que demostrar que sus consecuencias se desvían de la experiencia, o demostrar que sus predicciones no agotan las posibilidades de observación.
Niels Bohr
En conclusión, el autor quisiera afirmar que reconocemos solo dos buenas razones para rechazar una teoría que explica una amplia gama de fenómenos. En primer lugar, la teoría no es internamente consistente y, en segundo lugar, no está de acuerdo con los experimentos.
David Bohm
Anteriormente aprendimos de dónde viene la ecuación de Schrödinger, por qué se toma de allí y cómo se toma por varios métodos
Ahora, lo dividimos en dos ecuaciones reales. Para hacer esto, representamos psi en forma polar, :
, . , S -, - - :
, -, , , , S, , , , . , , . -.
— , . , , , . , , , .
, , , . . . , , , .
, , , . , ( - ). :
()
, , , : ,
-, :
using LinearAlgebra, SparseArrays, Plots
const ħ = 1.0546e-34 # J*s
const m = 9.1094e-31 # kg
const q = 1.6022e-19 # Kl
const nm = 1e-9 # m
const fs = 1e-12; # s
function wavefun()
gauss(x) = exp( -(x-x0)^2 / (2*σ^2) + im*x*k )
k = m*v/ħ
#
Vm = spdiagm(0 => V )
H = spdiagm(-1 => ones(Nx-1), 0 => -2ones(Nx), 1 => ones(Nx-1) )
H *= ħ^2 / ( 2m*dx^2 )
H += Vm
A = I + 0.5im*dt/ħ * H #
B = I - 0.5im*dt/ħ * H #
psi = zeros(Complex, Nx, Nt)
psi[:,1] = gauss.(x)
for t = 1:Nt-1
b = B * psi[:,t]
# A*psi = b
psi[:,t+1] = A \ b
end
return psi
end
dx = 0.05nm # x step
dt = 0.01fs # t step
xlast = 400nm
Nt = 260 # Number of time steps
t = range(0, length = Nt, step = dt)
x = [0:dx:xlast;]
Nx = length(x) # Number of spatial steps
a1 = 200nm
a2 = 200.5nm # 5
a3 = 205nm
a4 = 205.5nm
#V = [ a1<xi<a2 ? 2q : 0.0 for xi in x ] # 2 eV
V = [ a1<xi<a2 || a3<xi<a4 ? 2q : 0.0 for xi in x ] # 2 eV
x0 = 80nm # Initial position
σ = 20nm # gauss width
v = -120nm/fs;
@time Psi = wavefun()
P = abs2.(Psi);
function ψ(xi, j)
k = findfirst(el-> abs(el-xi)<dx, x)
k == nothing && ( k = 1 )
Psi[k, j]
end
function corpusculaz(n)
X = zeros(n, Nt)
X[:,1] = x0 .+ σ*randn(n)
for j in 2:Nt, i in 1:n
U = ħ/(2m*dx) * imag( ( ψ(X[i,j-1]+dx, j) - ψ(X[i,j-1]-dx, j) ) / ψ(X[i,j-1], j) )
X[i,j] = X[i,j-1] - U*dt
end
X
end
@time X = corpusculaz(20);
plot(x, P[:, 1], legend = false)
plot!(x, P[:, 80], legend = false)
scatter!( X[:,1], zeros(20) )
scatter!( X[:,80], zeros(20) )
. — , . :
, . Double-slit interference with ultracold metastable neon atoms — - .
using Random, Gnuplot, Statistics
#
function trapez(f, a, b, n)
h = (b - a)/n
result = 0.5*(f(a) + f(b))
for i in 1:n-1
result += f(a + i*h)
end
result * h
end
#
function rk4(f, x, y, h)
k1 = h * f(x , y )
k2 = h * f(x + 0.5h, y + 0.5k1)
k3 = h * f(x + 0.5h, y + 0.5k2)
k4 = h * f(x + h, y + k3)
return y + (k1 + 2*(k2 + k3) + k4)/6.0
end
const ħ = 1.055e-34 # J*s
const kB = 1.381e-23 # J*K-1
const g = 9.8 # m/s^2
const l1 = 76e-3 # m
const l2 = 113e-3 # m
const yh = 2.8e-3 # m
const d = 6e-6 # m
const b = 2e-6 # m
const a1 = 0.5(- d - b) #
const a2 = 0.5(- d + b)
const b1 = 0.5( d - b)
const b2 = 0.5( d + b)
const m = 3.349e-26 # kg
const T = 2.5e-3 # K
const σv = sqrt(kB*T/m) #
const σ₀ = 10e-6 # 10 mkm #
const σz = 3e-4 # 0.3 mm # z
const σk = m*σv / (ħ*√3) # 2e8 m/s #
v₀ = zeros(3)
k₀ = zeros(3);
: , , -, .
k
, . , , — . , , , . , , .
Quantum Mechanics And Path Integrals, A. R. Hibbs, R. P. Feynman, , 3.6 .
,
Z , . ,
, . , X, . :
, :
ε₀(t) = σ₀^2 + ( ħ/(2m*σ₀) * t )^2 + (ħ*t*σv/m)^2
s₀(t) = σ₀ + im*ħ/(2m*σ₀) * t
ρₓ(x, t) = exp( -x^2 / (2ε₀(t)) ) / sqrt( 2π*ε₀(t) )
t₁(v, z) = sqrt( 2*(l1-z)/g + (v/g)^2 ) - v/g
tf1 = t₁(v₀[3], 0) # s #
X1 = range(-100, stop = 100, length = 100)*1e-6
Z1 = range(0, stop = l1, length = 100)
Cron1 = range(0, stop = tf1, length = 100)
P1 = [ ρₓ(x, t) for t in Cron1, x in X1 ]
P1 /= maximum(P1); #
@gp "set title 'Wavefun before the slits'" xlab="Z, mkm" ylab="X, mkm"
@gp :- 1000Z1 1000000X1 P1 "w image notit"
— .
, :
function ρₓ(xᵢ, tᵢ)
Kₓ(xb, tb, xa, ta) = sqrt( m/(2im*π*ħ*(tb-ta)) ) * exp( im*m*(xb-xa)^2 / (2ħ*(tb-ta)) )
function subintrho(k)
ψₓ(x, t) = ( 2π*s₀(t) )^-0.25 * exp( -(x-ħ*k*t/m)^2 / (4σ₀*s₀(t)) + im*k*(x-ħ*k*t/m) )
subintpsi(x) = Kₓ(xᵢ, tᵢ, x, tf1) * ψₓ(x, tf1)
ψa = trapez(subintpsi, a1, a2, 200)
ψb = trapez(subintpsi, b1, b2, 200)
exp( -k^2 / (2σv^2) ) * abs2(ψa + ψb)
end
trapez(subintrho, -10σk, 10σk, 20) / sqrt( 2π*σv^2 )
end
t₂(v, z) = sqrt( 2*(l1+l2-z)/g + (v/g)^2 ) - v/g
tf2 = t₂(v₀[3], 0) # s #
X2 = range(-800, stop = 800, length = 200)*1e-6
Z2 = range(l1, stop = l2, length = 100)
Cron2 = range(tf1, stop = tf2, length = 100)
@time P2 = [ ρₓ(x, t) for t in Cron2, x in X2 ];
P2 /= maximum(P2[4:end,:]);
@gp "set title 'Wavefun after the slits'" xlab="t, s" ylab="X, mkm"
@gp :- Cron2[4:end] 1000000X2 P2[4:end,:] "w image notit"
2 :
:
, ,
function xbs(t, xo, yo, vo)
cosϕ = xo / sqrt( xo^2 + yo^2 )
sinϕ = yo / sqrt( xo^2 + yo^2 )
atnx = -ħ*t / (2m*σ₀^2)
sinatnx = atnx / sqrt( atnx^2 + 1)
cosatnx = 1 / sqrt( atnx^2 + 1)
cosϕt = cosϕ * cosatnx - sinϕ * sinatnx
#sinϕt = sinϕ*cosatnx + cosϕ*sinatnx
σ₀t = sqrt( σ₀^2 + ( ħ*t / (2*m*σ₀) )^2 )
vo*t + sqrt(xo^2 + yo^2) * σ₀t/σ₀ * cosϕt
end
@gp "set title 'Trajectories before slits'" xlab="t, s" ylab="X, mkm" # "set yrange [-10:10]"
@time for i in 1:80
x0 = randn()*σ₀
y0 = randn()*σ₀
v0 = randn()*σv*1e-4
prtclᵢ = [ xbs(t,x0,y0,v0) for t in Cron1 ]
@gp :- Cron1 1000000prtclᵢ "with lines notit lw 2 lc rgb 'black'"
# slits -4-> -2, 2->4 mkm
end
, , , , , . . . , .
Y , , . X . .
" " ,
function Uₓ(t, x)
γ = -m*x / ( ħ*(t-tf1) )
β = m/(2ħ) * ( 1/(t-tf1) + 1 / ( tf1*( 1 + (2m*σ₀^2 / (ħ*tf1) )^2 ) ) )
α = -( 4σ₀^2 * ( 1 + ( ħ*tf1 / (2m*σ₀^2) )^2 ) )^-1
f(x, u, t) = exp( ( α + im*β )*u^2 + im*γ*u )
C = f(x, a2, t) - f(x, a1, t) + f(x, b2, t) - f(x, b1, t)
H = trapez( u-> f(x, u, t) , a1, a2, 400) + trapez( u-> f(x, u, t) , b1, b2, 400)
return 1/(t-tf1) * ( x - 0.5/(α^2 + β^2) * ( β*imag(C/H) + α*real(C/H) - β*γ ) )
end
init() = bitrand()[1] ? rand()*(b2 - b1) + b1 : rand()*(a2 - a1) + a1
myrng(a, b, N) = collect( range(a, stop = b, length = N ÷ 2) )
n = 1
xx = 0
ξ = 1e-5
while xx < Cron2[end]-Cron2[1]
n+=1
xx += (ξ*n)^2
end
n
steps = [ (ξ*i)^2 for i in 1:n1 ]
Cronadapt = accumulate(+, steps, init = Cron2[1] )
function modelsolver(Np = 10, Nt = 100)
#xo = [ init() for i = 1:Np ] #
xo = vcat( myrng(a2, a1, Np), myrng(b1, b2, Np) ) #
xpath = zeros(Nt, Np)
xpath[1,:] = xo
for i in 2:Nt, j in 1:Np
xpath[i,j] = rk4(Uₓ, Cronadapt[i], xpath[i-1,j], steps[i] )
end
xpath
end
@time paths = modelsolver(20, n);
@gp "set title 'Trajectories after the slits'" xlab="t, s" ylab="X, mkm" "set yrange [-800:800]"
for i in 1:size(paths, 2)
@gp :- Cronadapt 1e6paths[:,i] "with lines notit lw 1 lc rgb 'black'"
end
- 4 , . 2
, : , , .
. , ,
function yas(t, xo, yo, vo)
cosϕ = xo / sqrt( xo^2 + yo^2 )
sinϕ = yo / sqrt( xo^2 + yo^2 )
atnx = -ħ*t / (2m*σ₀^2)
sinatnx = atnx / sqrt( atnx^2 + 1)
cosatnx = 1 / sqrt( atnx^2 + 1)
#cosϕt = cosϕ * cosatnx - sinϕ * sinatnx
sinϕt = sinϕ*cosatnx + cosϕ*sinatnx
σ₀t = sqrt( σ₀^2 + ( ħ*t / (2*m*σ₀) )^2 )
vo*t + sqrt(xo^2 + yo^2) * σ₀t/σ₀ * sinϕt
end
function modelsolver2(Np = 10)
Nt = length(Cronadapt)
xo = [ init() for i = 1:Np ]
#xo = vcat( myrng(a2, a1, Np), myrng(b1, b2, Np) )
xcoord = copy(xo)
ycoord = zeros(Np)
for i in 2:Nt, j in 1:Np
xcoord[j] = rk4(Uₓ, Cronadapt[i], xcoord[j], steps[i] )
end
for (i, x) in enumerate(xo)
y0 = randn()*yh
v0 = 0 #randn()*σv*1e-4
ycoord[i] = yas(Cronadapt[end], x, y0, v0)
end
xcoord, ycoord
end
@time X, Y = modelsolver2(100);
@gp "set title 'Impacts on the screen'" xlab="X, mm" ylab="Y, mm"# "set xrange [-1:1]"
@gp :- 1000X 1000Y "with points notit pt 7 ps 0.5 lc rgb 'black'"
, , . , ,