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Viewing changes to xprobqmc2.py

  • Committer: Paul Nation
  • Date: 2011-04-21 04:46:56 UTC
  • Revision ID: git-v1:dd4c966b490aa468dfbd28cef66694df4bf235c8

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xprobqmc2.py
 
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from qutip import *
 
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def probqmc2(E,kappa,gamma,g,wc,w0,wl,N,tlist,ntraj):
 
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        ida=qeye(N)
 
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        idatom=qeye(2)
 
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        a=tensor(destroy(N),idatom)
 
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        sm=tensor(ida,sigmam())
 
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        H=(w0-wl)*sm.dag()*sm+(wc-wl)*a.dag()*a+1j*g*(a.dag()*sm-sm.dag()*a)+E*(a.dag()+a)
 
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        #collapse operators
 
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        C1=sqrt(2*kappa)*a
 
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        C2=sqrt(gamma)*sm
 
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        C1dC1=C1.dag()*C1
 
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        C2dC2=C2.dag()*C2
 
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        #intial state
 
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        psi0=tensor(basis(N,0),basis(2,1))
 
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        # evolve and calculate expectation values
 
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        expt_list = mcwf_evolve(tlist, H, psi0, ntraj, [C1, C2], [C1dC1, C2dC2, a])
 
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        return expt_list[0], expt_list[1], expt_list[2]
 
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kappa=2
 
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gamma=0.2
 
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g=1
 
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wc=0
 
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w0=0
 
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wl=0
 
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E=0.5
 
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N=4
 
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tlist=linspace(0,10,100)
 
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ntraj=100
 
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start_time=time.time()
 
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count1, count2, infield = probqmc2(E,kappa,gamma,g,wc,w0,wl,N,tlist,ntraj)
 
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print 'time elapsed = ' +str(time.time()-start_time) 
 
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plot(tlist,real(count1))
 
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plot(tlist,real(count2))
 
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xlabel('Time')
 
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ylabel('Transmitted Intensity and Spontaneous Emission')
 
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show()
 
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