rpurcell.c

#include <math.h>
#include <stdlib.h>
#include "quac.h"
#include "operators.h"
#include "solver.h"
#include "petsc.h"

PetscErrorCode ts_monitor(TS,PetscInt,PetscReal,Vec,void*);

int main(int argc,char **args){
  PetscInt N_th,num_phonon,num_nv,init_phonon,steady_state_solve,steps_max;
  PetscReal time_max,dt,gam_res,gam_eff,gam_dep;
  double w_m,D_e,Omega,gamma_eff,lambda_eff,lambda_s,gamma_par,purcell_f,gamma_res,gamma_dep;
  double Q,alpha,kHz,MHz,GHz,THz,Hz,rate;
  operator a,nv;
  Vec rho;

  
  /* Initialize QuaC */
  QuaC_initialize(argc,args);

  
  /* Define units */
  GHz = 1e3;
  MHz = GHz*1e-3;
  kHz = MHz*1e-3;
  THz = GHz*1e3;
  Hz  = kHz*1e-3;
  alpha      = 0.01663;
  N_th       = 5;
  num_phonon = 100;
  num_nv     = 2;
  init_phonon = 12;
  steady_state_solve = 1;
  gam_res = 1.0;
  gam_eff = 1.0;
  gam_dep = 0.0;
    
  /* Get arguments from command line */
  PetscOptionsGetInt(NULL,NULL,"-num_nv",&num_nv,NULL);
  PetscOptionsGetInt(NULL,NULL,"-num_phonon",&num_phonon,NULL);
  PetscOptionsGetInt(NULL,NULL,"-n_th",&N_th,NULL);
  PetscOptionsGetInt(NULL,NULL,"-init_phonon",&init_phonon,NULL);
  PetscOptionsGetInt(NULL,NULL,"-steady_state",&steady_state_solve,NULL);
  PetscOptionsGetReal(NULL,NULL,"-gam_res",&gam_res,NULL);
  PetscOptionsGetReal(NULL,NULL,"-gam_eff",&gam_eff,NULL);
  PetscOptionsGetReal(NULL,NULL,"-gam_dep",&gam_dep,NULL);

  if (nid==0) printf("Num_phonon: %d N_th: %d num_nv: %d gam_res: %f gam_eff %f gam_dep %f\n",num_phonon,N_th,num_nv,gam_res,gam_eff,gam_dep);
  /* Define scalars to add to Ham */
  w_m        = 175*MHz*2*M_PI; //Mechanical resonator frequency
  lambda_s   = 0.1*MHz*2*M_PI;
  gamma_eff  = lambda_s*gam_eff;//1*MHz; //Effective dissipation rate
  gamma_res  = lambda_s*gam_res;
  gamma_dep  = lambda_s*gam_dep;

  print_dense_ham();

  create_op(num_phonon,&a);  
  create_op(2,&nv);

  /* Add terms to the hamiltonian */
  add_to_ham(w_m,a->n); // w_m at a
  
  add_to_ham(w_m,nv->n); // w_m nvt n

  /* Below 4 terms represent lambda_s (nvt + nv)(at + a) */
  //  add_to_ham_mult2(lambda_s,a->dag,nv->dag); //nvt at
  add_to_ham_mult2(0*lambda_s,nv->dag,a);  //nvt a
  add_to_ham_mult2(0*lambda_s,nv,a->dag);  //nv at
 //  add_to_ham_mult2(lambda_s,nv,a);   //nv a

  /* nv center lindblad terms */
  add_lin(gamma_eff,nv);
  add_lin(gamma_dep,nv->n); 
  add_lin_mult2(gamma_dep,nv,nv->dag); 

  /* phonon bath thermal terms */
  rate = gamma_res*(N_th+1);
  add_lin(rate,a);

  rate = gamma_res*(N_th);
  add_lin(rate,a->dag);
  
  create_full_dm(&rho);

  if (steady_state_solve==1) {
    steady_state(rho);
    purcell_f = 4*lambda_s*lambda_s/(gamma_eff+gamma_res+0.5*gamma_dep);
    rate = gamma_res/(gamma_res+purcell_f/(1+purcell_f/gamma_eff));
    if(nid==0) printf("Predicted cooling fraction: %f\n",rate);
  } else {
    set_ts_monitor(ts_monitor);
    //    set_initial_pop(a,init_phonon);
    //    set_initial_pop(nv,0);
    //    set_dm_from_initial_pop(rho);
    steady_state(rho);
    add_to_ham_mult2(lambda_s,nv->dag,a);  //nvt a
    add_to_ham_mult2(lambda_s,nv,a->dag);  //nv at
    time_max  = 15;
    dt        = 0.01;
    steps_max = 10000;
    time_step(rho,time_max,dt,steps_max);
  }

  destroy_op(&a);
  destroy_op(&nv);
  destroy_dm(rho);
  QuaC_finalize();
  return 0;
}
PetscErrorCode ts_monitor(TS ts,PetscInt step,PetscReal time,Vec dm,void *ctx){
   /* get_populations prints to pop file */

  get_populations(dm,time);
 
  PetscFunctionReturn(0);

}