[MalbertKerman]

The rocket folks call them "turbopumps" rather than "turbochargers," and most of them are powered by a separate combustion apparatus (with non-obvious terminology: if, after going through the turbine, the gas will then end up in the main combustion chamber then it's called a preburner, but if the gas will be discharged outside the main combustion chamber then it's called a gas generator).

There is one type that comes closer to a turbocharger's operation: the "tap-off cycle" runs the turbine on gas drawn from the main combustion chamber rather than using a separate combustor. Tap-off cycle engines aren't common but Blue Origin and Firefly are using them.