Your paper should be at most six pages in length, using at least 11-point fonts and at least 1-inch margins. You are strongly encouraged to prepare your paper using LaTeX; you might use this template (illustrating a few basic commands) to get started. If necessary, you can draw quantum circuits using the Qcircuit package. Feel free to ask the instructor and the course TAs for help with typesetting in addition to your chosen topic.
You may find it helpful to read a sample paper from a previous year's class. This is an example of a paper that is well-written and presented at an appropriate level, although it is a bit longer than your paper should be.
Most of these references are links to journal websites, which may not be accessible from outside the university. Please let me know if you have difficulty accessing any of these references, or if you would like additional references for some topic.