I'm reading up on semiconductor devices that rely on quantum tunneling, such as the tunnel diode and the TFET. The big advantage of these devices is apparently that "quantum tunneling is extremely fast".
Actually finding the speed of tunneling requires taking standard tunneling results (from solving the time-independent SE) and building wavepackets. This seems messy, and I don't see why those wavepackets should go particularly fast. What's the intuition here?