Nano 3 QHE experiment in ipython notebook

QHE.ipynb

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  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Quantum Hall effect experiment"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Supervisor: Guen P <guen@nbi.dk>"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import qdev; reload(qdev)\n",
      "from plotly.graph_objs import *\n",
      "from plotly.widgets import GraphWidget\n",
      "from plotly.grid_objs import Column, Grid\n",
      "import plotly.plotly as py\n",
      "from time import sleep\n",
      "from qdev_conf import set_logging_config\n",
      "set_logging_config('INFO')"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 580
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Load experiment"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "nano3_json = {\n",
      "    \"experiment_variables\": {\n",
      "        \"Vxx\": \"lockin2.R\",\n",
      "        \"Vxy\": \"lockin1.R\",\n",
      "        \"bias_voltage\": \"lockin1.amplitude\",\n",
      "        \"field\": \"magnet.field\",\n",
      "#         \"Isd\": \"lockin3.amplitude\",\n",
      "        \"manual_variables\": {\n",
      "            \"bias_resistor\": 100e3\n",
      "        }\n",
      "    },\n",
      "    \"metadata\": {\n",
      "        \"group\": \"test\"\n",
      "    }\n",
      "}\n",
      "nano3 = qdev.load_experiment(nano3_json)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 581
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "magnet = nano3.instruments.magnet\n",
      "Vxx = nano3.Vxx\n",
      "Vxy = nano3.Vxy\n",
      "current = nano3.bias_voltage.get()/nano3.bias_resistor.get()\n",
      "timenow = nano3.seconds"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 582
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Create data grid and upload to server"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "Vxx_vs_B = Scatter(x=[magnet.field.get()], y=[Vxx.get()], name='$V_{xx} (V)$')\n",
      "Vxy_vs_B = Scatter(x=[magnet.field.get()], y=[Vxy.get()], name='$V_{xy} (V)$')"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 625
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "column_0 = Column([0], 'time (s)')\n",
      "column_1 = Column(Vxx_vs_B['x'], 'B (T)')\n",
      "column_2 = Column(Vxx_vs_B['y'], 'Vxx (V)')\n",
      "column_3 = Column(Vxy_vs_B['y'], 'Vxy (V)')\n",
      "\n",
      "grid = Grid([column_0, column_1, column_2, column_3])"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 626
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "exp_name = 'Nano 3 QHE test 7'\n",
      "meta_json = nano3.snapshot_string()\n",
      "grid_url = py.grid_ops.upload(grid, exp_name, meta=meta_json)\n",
      "grid_url"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "2015-02-17 01:52:41,920 [INFO] root: Taking snapshot...\n"
       ]
      },
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 628,
       "text": [
        "u'http://plotly.fys.ku.dk/~guen/148/'"
       ]
      }
     ],
     "prompt_number": 628
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Create graph"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "g = GraphWidget()"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 629
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Setting the graph axes"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "layout = Layout(\n",
      "    title='Quantum Hall effect',\n",
      "    yaxis=YAxis(\n",
      "        title='$V_{xx}, V_{xy} (V)$'\n",
      "    ),\n",
      "    xaxis=XAxis(\n",
      "        title='$B (T)$'),\n",
      "    showlegend=True\n",
      ")"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 630
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "g"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 631
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "g.delete_traces([0])\n",
      "g.add_traces([Vxx_vs_B, Vxy_vs_B])\n",
      "g.relayout(layout)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 633
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Set the field setpoint to 2T and start field sweep while measuring Vxx and Vxy."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "magnet.field_sweep_rate.set(0.2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 638
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "magnet.field_setpoint.set(0)\n",
      "timenow.reset()\n",
      "magnet.go_to_setpoint()\n",
      "lastrefresh = 0\n",
      "while magnet.field.get()>0:\n",
      "    row = [timenow.get(), magnet.field.get(), Vxx.get(), Vxy.get()]\n",
      "    Vxx_vs_B['x'].append(row[1])\n",
      "    Vxx_vs_B['y'].append(row[2])\n",
      "    Vxy_vs_B['x'].append(row[1])\n",
      "    Vxy_vs_B['y'].append(row[3])\n",
      "    py.grid_ops.append_rows([row], grid_url=grid_url)\n",
      "    \n",
      "    #only refresh graph every 2 seconds\n",
      "    if (np.mod(int(timenow.get()),2) == 0) & ((timenow.get()-lastrefresh) > 1):\n",
      "        data = {'x': [Vxx_vs_B['x'], Vxy_vs_B['x']], 'y': [Vxx_vs_B['y'], Vxy_vs_B['y']]}\n",
      "        g.restyle(data)\n",
      "        lastrefresh = timenow.get()\n",
      "        \n",
      "    sleep(0.1)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 640
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Export graph"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "data = Data([Vxx_vs_B, Vxy_vs_B])\n",
      "fig = Figure(data=data, layout=layout)\n",
      "py.plot(fig, filename=exp_name + '_graph')"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 641,
       "text": [
        "u'http://plotly.fys.ku.dk/~guen/149'"
       ]
      }
     ],
     "prompt_number": 641
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Other functions"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "magnet.field_setpoint.set(2)\n",
      "magnet.go_to_setpoint()"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 637
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "magnet.hold() # stop the magnet"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 643
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "magnet.go_to_zero() # go to zero field"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 577
    }
   ],
   "metadata": {}
  }
 ]
}