docs/examples/mbs-lambda-weak-pulse-more-atoms-with-coupling.ipynb

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   "source": [
    "# Λ-Type Three-Level: Weak Pulse, With Coupling"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Define and Solve"
   ]
  },
  {
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   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "mb_solve_json = \"\"\"\n",
    "{\n",
    "  \"atom\": {\n",
    "    \"fields\": [\n",
    "      {\n",
    "        \"coupled_levels\": [[0, 1]],\n",
    "        \"detuning\": 0.0,\n",
    "        \"detuning_positive\": true,\n",
    "        \"label\": \"probe\",\n",
    "        \"rabi_freq\": 1.0e-3,\n",
    "        \"rabi_freq_t_args\": \n",
    "          {\n",
    "             \"ampl\": 1.0,\n",
    "             \"centre\": 0.0,\n",
    "             \"fwhm\": 1.0\n",
    "          },\n",
    "        \"rabi_freq_t_func\": \"gaussian\"\n",
    "      },\n",
    "      {\n",
    "        \"coupled_levels\": [[1, 2]],\n",
    "        \"detuning\": 0.0,\n",
    "        \"detuning_positive\": false,\n",
    "        \"label\": \"coupling\",\n",
    "        \"rabi_freq\": 5.0,\n",
    "        \"rabi_freq_t_args\": \n",
    "        {\n",
    "          \"ampl\": 1.0,\n",
    "          \"fwhm\": 0.2,\n",
    "          \"on\": -1.0, \n",
    "          \"off\": 9.0\n",
    "          },\n",
    "        \"rabi_freq_t_func\": \"ramp_onoff\"\n",
    "      }\n",
    "    ],\n",
    "    \"num_states\": 3\n",
    "  },\n",
    "  \"t_min\": -2.0,\n",
    "  \"t_max\": 10.0,\n",
    "  \"t_steps\": 120,\n",
    "  \"z_min\": -0.2,\n",
    "  \"z_max\": 1.2,\n",
    "  \"z_steps\": 100,\n",
    "  \"z_steps_inner\": 2,\n",
    "  \"interaction_strengths\": [10.0, 10.0],\n",
    "  \"savefile\": \"mbs-lambda-weak-pulse-more-atoms-no-coupling\" \n",
    "}\n",
    "\"\"\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from maxwellbloch import mb_solve\n",
    "mbs = mb_solve.MBSolve().from_json_str(mb_solve_json)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%time Omegas_zt, states_zt = mbs.mbsolve(recalc=False)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Field Output"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import matplotlib.pyplot as plt\n",
    "%matplotlib inline\n",
    "import seaborn as sns\n",
    "import numpy as np\n",
    "sns.set_style('darkgrid')\n",
    "\n",
    "fig = plt.figure(1, figsize=(16, 6))\n",
    "ax = fig.add_subplot(111)\n",
    "cmap_range = np.linspace(0.0, 1.0e-3, 11)\n",
    "cf = ax.contourf(mbs.tlist, mbs.zlist,\n",
    "                 np.abs(mbs.Omegas_zt[0]/(2*np.pi)),\n",
    "                 cmap_range, cmap=plt.cm.Blues)\n",
    "ax.set_title('Rabi Frequency ($\\Gamma / 2\\pi $)')\n",
    "ax.set_xlabel('Time ($1/\\Gamma$)')\n",
    "ax.set_ylabel('Distance ($L$)')\n",
    "for y in [0.0, 1.0]:\n",
    "    ax.axhline(y, c='grey', lw=1.0, ls='dotted')\n",
    "plt.colorbar(cf);"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import matplotlib.pyplot as plt\n",
    "%matplotlib inline\n",
    "import seaborn as sns\n",
    "import numpy as np\n",
    "sns.set_style('darkgrid')\n",
    "\n",
    "fig = plt.figure(1, figsize=(16, 6))\n",
    "ax = fig.add_subplot(111)\n",
    "cmap_range = np.linspace(0.0, 10.0, 11)\n",
    "cf = ax.contourf(mbs.tlist, mbs.zlist,\n",
    "                 np.abs(mbs.Omegas_zt[1]/(2*np.pi)),\n",
    "                 cmap_range, cmap=plt.cm.Greens)\n",
    "ax.set_title('Rabi Frequency ($\\Gamma / 2\\pi $)')\n",
    "ax.set_xlabel('Time ($1/\\Gamma$)')\n",
    "ax.set_ylabel('Distance ($L$)')\n",
    "for y in [0.0, 1.0]:\n",
    "    ax.axhline(y, c='grey', lw=1.0, ls='dotted')\n",
    "plt.colorbar(cf);"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Analysis\n",
    "\n",
    "With no coupling, the weak probe pulse is absorbed just like in the two-level atom case."
   ]
  }
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