-
Notifications
You must be signed in to change notification settings - Fork 0
/
Forward_FT.cpp
288 lines (180 loc) · 8.65 KB
/
Forward_FT.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
#include <iostream>
#include <cstdlib>
#include <cmath>
#include <fstream>
#include <time.h>
#include <sstream>
using namespace std;
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void Evol_Temp(int N_bath, double Lambda, int N_cond, ofstream &arquivo){
double r = (pow(2.0,1.0/3.0) + pow(2.0,-1.0/3.0) -1)/6.0;
double c[4] = {r + 1.0/2.0, -r, -r, r + 1.0/2.0};
double d[4] = {2.0*r + 1.0, -4.0*r - 1.0, 2.0*r + 1.0, 0.0};
double T_step = 0.01;
// system coordinates
double *Q = (double *) calloc(N_cond, sizeof(double));
double *P = (double *) calloc(N_cond, sizeof(double));
// sample coordinates
double *x1 = (double *) calloc(N_cond, sizeof(double));
double *y1 = (double *) calloc(N_cond, sizeof(double));
double *px1 = (double *) calloc(N_cond, sizeof(double));
double *py1 = (double *) calloc(N_cond, sizeof(double));
// heat bath coordinates for each mode
double **X = (double **) calloc(N_bath , sizeof(double*));
double **Y = (double **) calloc(N_bath , sizeof(double*));
double **Px = (double **) calloc(N_bath, sizeof(double*));
double **Py = (double **) calloc(N_bath, sizeof(double*));
int i, j, h, l;
for(i = 0; i < N_bath; i++){
X[i] = (double*) calloc(N_cond, sizeof(double));
Y[i] = (double*) calloc(N_cond, sizeof(double));
Px[i] = (double*) calloc(N_cond, sizeof(double));
Py[i] = (double*) calloc(N_cond, sizeof(double));
}
double *E_i = (double *) calloc(N_cond, sizeof(double));
double *E_f = (double *) calloc(N_cond, sizeof(double));
// quartic parameter 'a'
double A = 0.1;
double E_part = 0.1968*(100);
double E_bath = 0.01/(1000);
double k0 = 0.3;
double delta_k = 2 * k0;
double k = k0;
double Quant;
// Protocol parameters
int tau_relax = 100000; // chaotic relaxation of bath
int tau = 500000; //200000; // thermalization system-bath
int tau_prot = 120000; //50000 // time of protocol
// Sampling initial conditions for each heat bath mode.
for(i = 0; i < N_bath; i++){
j = 0;
while(j < N_cond){
double m = rand()%4;
if(m == 0){
y1[j] = (2.0*rand()/RAND_MAX - 1) / pow(A,1.0/4.0);
px1[j] = (2.0*rand()/RAND_MAX - 1) * pow(2.0 * E_bath, 1.0/2.0);
py1[j] = (2.0*rand()/RAND_MAX - 1) * pow(2.0 * E_bath, 1.0/2.0);
x1[j] = pow(-1,rand()%2) * sqrt(-y1[j]*y1[j] + sqrt(y1[j]*y1[j]*y1[j]*y1[j] - A*(2*px1[j]*px1[j] + 2*py1[j]*py1[j] + A*y1[j]*y1[j]*y1[j]*y1[j] - 4*E_bath)))/sqrt(A);
}
else if(m == 1){
x1[j] = (2.0*rand()/RAND_MAX - 1) * pow(4.0 * E_bath/A, 1.0/4.0);
px1[j] = (2.0*rand()/RAND_MAX - 1) * pow(2.0 * E_bath, 1.0/2.0);
py1[j] = (2.0*rand()/RAND_MAX - 1) * pow(2.0 * E_bath, 1.0/2.0);
y1[j] = pow(-1,rand()%2) * sqrt(-x1[j]*x1[j] + sqrt(x1[j]*x1[j]*x1[j]*x1[j] -A*(2*px1[j]*px1[j] + 2*py1[j]*py1[j] + A*x1[j]*x1[j]*x1[j]*x1[j] - 4*E_bath)))/sqrt(A);
}
else if(m == 2){
x1[j] = (2.0*rand()/RAND_MAX - 1) * pow(4.0 * E_bath/A, 1.0/4.0);
y1[j] = (2.0*rand()/RAND_MAX - 1) * pow(4.0 * E_bath/A, 1.0/4.0);
py1[j] = (2.0*rand()/RAND_MAX - 1) * pow(2.0 * E_bath, 1.0/2.0);
px1[j] = pow(-1,rand()%2) * sqrt(2*E_bath - A*(x1[j]*x1[j]*x1[j]*x1[j] + y1[j]*y1[j]*y1[j]*y1[j])/2 - x1[j]*x1[j]*y1[j]*y1[j] - py1[j]*py1[j]);
}
else{
x1[j] = (2.0*rand()/RAND_MAX - 1) * pow(4.0 * E_bath/A, 1.0/4.0);
y1[j] = (2.0*rand()/RAND_MAX - 1) * pow(4.0 * E_bath/A, 1.0/4.0);
px1[j] = (2.0*rand()/RAND_MAX - 1) * pow(2.0 * E_bath, 1.0/2.0);
py1[j] = pow(-1,rand()%2) * sqrt(2*E_bath - A*(x1[j]*x1[j]*x1[j]*x1[j] + y1[j]*y1[j]*y1[j]*y1[j])/2 - x1[j]*x1[j]*y1[j]*y1[j] - px1[j]*px1[j]);
}
if(!isnan(x1[j]) && !isnan(y1[j]) && !isnan(px1[j]) && !isnan(py1[j])){
X[i][j] = x1[j];
Y[i][j] = y1[j];
Px[i][j] = px1[j];
Py[i][j] = py1[j];
Q[j] = sqrt(2.0 * E_part / k) * sin(j*2.0*M_PI/N_cond);
P[j] = sqrt(2.0 * E_part) * cos(j*2.0*M_PI/N_cond);
j++;
}
}
}
/* Relaxing the bath modes into chaotic behavior before coupling to the system
(see ref: "https://iopscience.iop.org/article/10.1088/1751-8121/ab9a78/meta") */
for(i = 0; i < tau_relax ; i++){
for(j = 0; j < N_cond; j++){
for(l = 0; l < 4; l++){
for(h = 0; h < N_bath; h++){
Px[h][j] += - c[l] * T_step * (A * X[h][j]*X[h][j]*X[h][j] + X[h][j]*Y[h][j]*Y[h][j]);
Py[h][j] += - c[l] * T_step * (A * Y[h][j]*Y[h][j]*Y[h][j] + Y[h][j]*X[h][j]*X[h][j]);
}
for(h = 0; h < N_bath; h++){
X[h][j] += + d[l] * T_step * Px[h][j];
Y[h][j] += + d[l] * T_step * Py[h][j];
}
}
}
}
// Interaction system-bath until thermalization
/* We use fourth-order symplectic integration to integrate Hamilton's equations. See:
"https://www.sciencedirect.com/science/article/abs/pii/016727899090019L?via%3Dihub"*/
for(i = 0; i < tau ; i++){
for(j = 0; j < N_cond; j++){
for(int l = 0; l < 4; l++){
Quant = 0.0;
for(h= 0; h < N_bath; h++){
Quant += X[h][j];
}
P[j] += - c[l] * T_step * (Lambda * (Quant) + k * Q[j]);
for(h= 0; h < N_bath; h++){
Px[h][j] += - c[l] * T_step * (A * X[h][j]*X[h][j]*X[h][j] + X[h][j]*Y[h][j]*Y[h][j] + Lambda * Q[j]);
Py[h][j] += - c[l] * T_step * (A * Y[h][j]*Y[h][j]*Y[h][j] + Y[h][j]*X[h][j]*X[h][j]);
X[h][j] += + d[l] * T_step * Px[h][j];
Y[h][j] += + d[l] * T_step * Py[h][j];
}
// Position should be the last one to be implemented
Q[j] += + d[l] * T_step * P[j];
}
}
}
for(j = 0; j < N_cond; j++){
E_i[j] = P[j]*P[j]/2.0 + k * Q[j]*Q[j]/2.0 ;
}
// Operating the protocol on the system after thermalization
for(i = 0; i < tau_prot; i++){
k = k0 + delta_k*(i)/(tau_prot);
for(j = 0; j < N_cond; j++){
for(int l = 0; l < 4; l++){
P[j] += - c[l]*T_step * (k * Q[j]);
Q[j] += + d[l]*T_step * P[j];
}
}
}
// writting a file with energies during the system interaction with the chaotic bath
for(j = 0; j < N_cond; j++){
E_f[j] = P[j]*P[j]/2.0 + k * Q[j]*Q[j]/2.0 ;
arquivo << showpos << scientific << E_f[j] << " " << E_i[j] << " "<< k << " " << E_f[j] - E_i[j] << "\n" ;
}
free(Q);
free(P);
free(x1);
free(y1);
free(px1);
free(py1);
free(X);
free(Y);
free(Px);
free(Py);
free(E_i);
free(E_f);
}
////////////////////////////////////----------Main -----//////////////////////////////////////////////////////
int main(int argn, char **arg){
if(argn != 4){
cout << "\n";
cout << "Entrada Inválida!\n";
cout << "Entre com as seguintes variáveis: Número de Condições Iniciais, Número de Iterações e o parâmetro A.\n\n";
}
// Picking parameters
int N_bath = atoi(arg[1]); // number of bath modes
double Lambda = atof(arg[2]); // coupling constant
int N_cond = atoi(arg[3]); // number of initial samples of the system
double Lambda1 = Lambda/sqrt(N_bath);
double t_0 = clock();
ofstream arquivo;
arquivo.open (("For_" + string(arg[1]) + "_" + string(arg[2]) + "_" + string(arg[3]) + ".txt").c_str());
Evol_Temp(N_bath, Lambda1, N_cond, arquivo);
arquivo.close();
double T_process = (clock()-t_0)/CLOCKS_PER_SEC;
cout << "\n";
cout << "Cálculo Encerrado! ";
cout << "Tempo de Processamento [em segundos]: " << T_process;
cout << "\n\n";
return 0;
}