Research at the Institute for Theoretical Physics (ITP) at Utrecht University covers high-energy physics (elementary particles, quantum gravity, string theory), cosmology (early universe, cosmic microwave background, inflation, gravitational waves), quantum matter (superconductivity, spintronics, Bose-Einstein condensation, quantum Hall effect, quantum computing), and soft matter and biophysics (colloidal self-assembly, iontronics, cell motility, stochastic population dynamics).
The institute offers students with an MSc degree the opportunity to enter a four-year’s PhD program in theoretical physics. Apart from their research project PhD students are required to take a number of courses, almost always in the context of the Dutch Research School for Theoretical Physics. They also act as teaching assistants for about ten percent of their working time (usually some form of tutoring in the MSc and BSc physics courses).
Note that PhD students in the Netherlands in most cases are employed with a salary rather than a stipend, see Obtaining a PhD Position. Openings for PhD positions in the ITP can be found under Vacancies.