Angular Material is targeted at evergreen browsers. This is why an unsupported browser page for IE <= 10 is provided for you.

How does it work?

the conditional comment is available in index.blade.php

<!--[if lte IE 10]>
   <script type="text/javascript">document.location.href = '/unsupported-browser'</script>
<![endif]-->

You can also change the design & text of the unsupported page, located at resources/views/unsupported_browser.blade.php.