title: md-checkbox single check in angular js
body: <p>I have problem on md-checkbox.<br>
  I need to use single selection of check but I couldn't make it.<br>
  I referred md-radio-button for groupings but I don't want to use radio button.       </p>
  
  <p>Below is my code:    </p>
  
  <pre><code>&lt;ul&gt;
      &lt;li&gt;
          &lt;md-checkbox ng-model="data1"  aria-label="Checkbox 1"&gt;
              Full Time
          &lt;/md-checkbox&gt;
      &lt;/li&gt;
      &lt;li&gt;
          &lt;md-checkbox ng-model="data2" aria-label="Checkbox 1"&gt;
              6AM - 12 PM
          &lt;/md-checkbox&gt;
      &lt;/li&gt;
      &lt;li&gt;
          &lt;md-checkbox ng-model="data3" aria-label="Checkbox 1"&gt;
              12PM - 9PM
          &lt;/md-checkbox&gt;
      &lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>Can anyone help me.  </p>