You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
Copy file name to clipboardExpand all lines: QuantumToolbox.jl/time_evolution/rabi.qmd
+9-9Lines changed: 9 additions & 9 deletions
Original file line number
Diff line number
Diff line change
@@ -6,12 +6,12 @@ date: 2025-01-17 # last update (keep this comment as a reminder)
6
6
engine: julia
7
7
---
8
8
9
-
Inspirations taken from this [QuTiP tutorial](https://nbviewer.org/urls/qutip.org/qutip-tutorials/tutorials-v5/time-evolution/004_rabi-oscillations.ipynb) by J.R. Johansson, P.D. Nation, and C. Staufenbiel
9
+
Inspirations taken from [this QuTiP tutorial](https://nbviewer.org/urls/qutip.org/qutip-tutorials/tutorials-v5/time-evolution/004_rabi-oscillations.ipynb) by J.R. Johansson, P.D. Nation, and C. Staufenbiel
10
10
11
-
In this notebook, the usage of `QuantumToolbox.sesolve` and `QuantumToolbox.mesolve` will be demonstrated with Jaynes-Cummings model to observe Rabi oscillations in the isolated case and the dissipative case. In dissipative case, a bosonic environment would interact with the cavity and two-level atom in JC model.
11
+
In this notebook, the usage of `QuantumToolbox.sesolve` and `QuantumToolbox.mesolve` will be demonstrated with Jaynes-Cummings model (JC model) to observe Rabi oscillations in the isolated case and the dissipative case. In the dissipative case, a bosonic interacts with the cavity and the two-level atom in the JC model.
12
12
13
13
## Introduction to Jaynes-Cumming model
14
-
Jaynes-Cummings (JC) model, a simplest quantum mechanical model for light-matter interaction, describes an atom interacting with an external electromagnetic field. To simplify the interaction, JC model considered a two-level atom interacting with a single bosonic mode (or you can consider it a single-mode cavity).
14
+
The JC model is a simplest quantum mechanical model for light-matter interaction, describing an atom interacting with an external electromagnetic field. To simplify the interaction, the JC model consideres a two-level atom interacting with a single bosonic mode, which can also be thought of as a single-mode cavity.
- $\hat{\sigma}$ : Lowering operator of atom. Equivalent to $|g\rangle\langle e|$
36
36
37
-
By applying [rotating wave approximation (RWA)](https://en.wikipedia.org/wiki/Rotating-wave_approximation), the counter rotating terms ($\hat{\sigma} \cdot \hat{a}$ and its Hermitian conjugate) are ignored, yielding
37
+
By applying the [rotating wave approximation (RWA)](https://en.wikipedia.org/wiki/Rotating-wave_approximation), the counter rotating terms ($\hat{\sigma} \cdot \hat{a}$ and its Hermitian conjugate) are ignored, yielding
For the case of JC model being isolated, i.e., no interaction with the surrounding environment, the time-evolution is governed solely by Schrödinger equation $\hat{H}|\psi(t)\rangle = \partial_t|\psi(t)\rangle$. Using`QuantumToolbox.sesolve` is ideal for pure state evolution.
72
+
For the case of the JC model being isolated, i.e., with no interaction with the surrounding environment, the timeevolution is governed solely by the Schrödinger equation, $\hat{H}|\psi(t)\rangle = \partial_t|\psi(t)\rangle$. The`QuantumToolbox.sesolve`function is ideal for simulating such pure state evolution.
73
73
74
-
For the context of [Rabi problem](https://en.wikipedia.org/wiki/Rabi_problem), we set the initial state $\psi_0 = |e\rangle \otimes |0\rangle$, where $|e\rangle$ is the excited state of atom and $|0\rangle$ is the vacuum state of cavity.
74
+
For the context of [Rabi problem](https://en.wikipedia.org/wiki/Rabi_problem), we set the initial state as $\psi_0 = |e\rangle \otimes |0\rangle$, where $|e\rangle$ is the excited state of the atom and $|0\rangle$ is the vacuum state of the cavity.
75
75
76
76
```{julia}
77
77
e_ket = basis(2,0)
@@ -114,7 +114,7 @@ In the above plot, the behaviour of the energy exchange between the atom and the
114
114
115
115
## Dissipative case
116
116
117
-
In contrast to isolated evolution, a factual system interacts with its surrounding environments, resulting in energy/particle exchange. We are currently interested in observing JC model's Rabi oscillation with the addition of interaction with the external thermal field.
117
+
In contrast to isolated evolution, a realistic system interacts with its surrounding environment, leading to energy or particle exchange. Here, we focus on observing the Rabi oscillations of the JC model with the inclusion of interactions with an external environment at some finite temperature.
118
118
119
119
We start by reviewing the interaction Hamiltonians between the thermal field and atom/cavity
120
120
@@ -131,7 +131,7 @@ where for the $l$-th mode
131
131
- $\beta_l$ is the coupling strength with the cavity
132
132
- $\hat{b}_l$ is the annihilation operator
133
133
134
-
Follow the aforementioned RWA and the standard procedure of [Born-Markovian approximation](https://en.wikiversity.org/wiki/Open_Quantum_Systems/The_Quantum_Optical_Master_Equation), we obtain $\kappa$, the cavity dissipation rate, and $\gamma$, the atom dissipation rate. Therefore, the time evolution of the dissipative JC model can be described by the [Lindblad master equation](https://en.wikipedia.org/wiki/Lindbladian)
134
+
By applying the aforementioned RWA and following the standard procedure of the [Born-Markovian approximation](https://en.wikiversity.org/wiki/Open_Quantum_Systems/The_Quantum_Optical_Master_Equation), we obtain $\kappa$, the cavity dissipation rate, and $\gamma$, the atom dissipation rate. Consequently, the time evolution of the dissipative JC model is described by the [Lindblad master equation](https://en.wikipedia.org/wiki/Lindbladian).
axislegend(ax_me_; position = :rt, labelsize = 15)
221
221
display(fig_me_);
222
222
```
223
-
Despite the asymptotic behaviour persisting, one can see that they no longer approach zero and instead find a steady condition above zero. That is, the system is thermalized by the environment.
223
+
Despite the persistence of the asymptotic behaviour, the system no longer approaches zero but instead reaches a steady-state above zero. This indicates that the system has been thermalized by the environment.
0 commit comments