At Chalmers, all PhD positions are announced centrally. Just select the Computer Science and Engineering department, and then PhD Student Positions. There you can also subscribe to future announcements.
If you email me directly to ask for a PhD position or internship during the summer, please *first* look at my homepage, my research interest, and some of my research papers. If your cover letter looks like it has been mass-mailed, I will not respond.
Unfortunately, I usually cannot accept summer interns. Chalmers is mostly closed during the summer and most people (including me) will take some vacation during this time.
If you want to increase your chances to work with me, it is probably better to come and complete a master thesis.