Simulation of three level system of an atom

[START]

Dear all,

I am new to QuTiP. I am working on to simulate a three level system of an atom and looking to get the population of all states. Can you please suggest any documentation (or some previous example) which could help me to do this?

Thanks,

Rishab

[latifeh iri]

Dear Rishab,

Here is the link (https://qutip.org/docs/4.0.2/modules/qutip/three_level_atom.html) for three level systems for different configurations. You can also follow as below.

# first, define the three atomic states:

one = basis(3,0)

two = basis(3,1)

three = basis(3,2)

# states and atomic operators

sig11 = one * one.dag()

sig22 = two * two.dag()

sig33 = three * three.dag()

sig12 = one * two.dag()

sig32 = three * two.dag()

# destruction operator

a = tensor(identity(3),destroy(N))

N = 10  # limit the photon space to N dimensions

# the tensor space will be in the form |atom> (*) |photon>:

Sig11 = tensor(sig11,identity(N))

Sig22 = tensor(sig22,identity(N))

... etc fill in the rest

# define the Hamiltonian
H = H0 + H12 + H21 + H23 + H32

psi0 = tensor(basis(N, n), basis(3,0)).unit()
tlist = linspace(0, 100, 1500)
res = mesolve(H , psi0, tlist, [Sig11])

# population for P1 as an example

P1 = res.expect[0]

#

plt.plot(tlist, P1)