naysayers that arent engineers and dont understand his question… get lost. you havent got a clue.
he isnt thinking of using a standard a/c clutch at all. he is thinking of something like the freewheel setup on a bmx and 10-speed bike. you dont need to use a clutch at the turbo shaft. you probably need it elsewhere.
1st gear in a dodge 3-speed automatic uses a freewheel setup. its a bunch of rollers and a housing with ramps that “catch” a shaft when power is applied and allow it to spin freely when the power isnt applied. its called the overrun clutch.
its possible and will require a much wider custom dual-cartridge ball bearing center section and the turbine wheel/shaft assy has to have a longer shaft. you place a cartridge near the turbine and another near the compressor and leave the center of the shaft open for the overrun clutch assembly and a gearbox setup. youll also need to provide oil to the bearing cartridges and the overrun clutch setup.
the theory part of things. you calculate the airflow needed (lb/min) at say 1500-2000rpms for the engine, taking volumetric efficiency into account.
then look at the compressor map for the turbo that you are using and look at the airflow at the bottom and the pressure ratio on the left side that you want to have at your low rpm point. at that point (or near) should be another line telling you the shaft speed to make this pressure based on the airflow. set your gearbox that drives the turbo shaft to meet that compressor speed at the rpm point. you will want something like an ac clutch to turn off the system when at idle and when the full spool boost is reached. given the gearbox ratio that you need to get actual boost at such a low rpm, you will overspeed the turbo with the engine high rpms.
the system will work should work well though it will be difficult and expensive to manufacture for an individual and difficult to plumb.
more realistic options?
-small shot of nitrous on the bottom end and shut it off at full boost.
-VNT turbo. greatly increases the velocity of the nozzle aimed at the turbine. i think a newer powerstroke ford uses a VNT turbo. take the exhaust housing from that and a T4 or GT compressor and mate the two. should work fairly well and be reasonable for a custom turbo shop to put together.
-HX35 with a modified divided turbine housing (or any turbo with the divided housing like the evo). block off one side of the turbine housing with an inconel throttle plate in the low rpms till the boost comes up. 
Brian