Yes. And another problem is that there's such a thing as electron confinement. It's the same effect as in the "particle in a box" solution of the Schrödinger eq

Yes. And another problem is that there's such a thing as electron confinement. It's the same effect as in the "particle in a box" solution of the Schrödinger equation where the particle's probability is zero next to an infinitely high potential. The gate oxide is a very high potential for an electron and therefore the actual current flows close to the center of the wire. So instead of a diameter of 10 silicon atoms, you now have something like 5 or so where the current flows. Imagine that you place a single atom wrongly in the center of your nanowire. Now you have a scattering target exactly where your first mode (the most populated one) has its maximum. It's effectively like putting a block of concrete on a one-way street. There's no way the electrons could go around the defect. It could completely stop your nanowire from working or at least deteriorate its properties severely. That's why imec tries to use 3 nanowires per transistor. It'd be quite the show stopper if some of your transistors wouldn't work at all.