In physics, original research is generally published in journal articles and conference proceedings. Here are some of the resources you can use to search for articles on a topic or to access a specific article by title.
Some professional organizations (like the American Physical Society or SPIE) maintain digital libraries where you can search for articles published in their journals.
You can search for articles and conference proceedings from a wide range of sources at one time with databases, which are not restricted to a specific publisher.