probe - How will Yuri Milner and Stephen Hawking's nanobots decelerate and transmit data upon arrival at Alpha Centauri?

Solar sails often suggest a couple of modes for slowing down.

1) Have a launch laser at the target location to slow it down the same way. Assumes much infrastructure.

2) Use the solar energy of the target sun to slow the sail down. I.e. Turn it around and spend a longer time decelerating as you get closer and closer.

3) There was a model, where the main sail had a second larger sail that would fly with it, during acceleration, but upon cruise would separate, and advance in front of the main sail. Then the launch laser would target the larger sail, to reflect the energy back on the smaller sail to slow it down. (Lots of tricky bits in that approach).