Building a DIY synchronized atomic clock from scratch—where to start and what components?

Hello, I 'm a student and I need your help. I wanna make a synchronized atomic clock. What should I start from? I am gonna make it from zero.

Some sugestion to start from here:

http://www.micro-examples.com/public/microex-navig/doc/100-p16f84-led-dcf-clock.html