**3. Conclusions**

In this short review paper, I have discussed some of the most unusual quantum transport effects that have been recently observed in silicon CMOS compatible devices. If from one side valley-orbital effects can be linked to the novel observation of effects such as for example the SU(4) Kondo [8] and the Fano-Kondo ones [10], from another side single-atom transistors and other silicon devices [4,12–15,46,48], because of their immunity to thermal and non-adiabatic detrimental effects, have demonstrated the ability to provide a unique environment for the ultra-fast control of electrons [12–15,46,48]. It is also very interesting to observe that even in the quantum pumping regime, the special valley-orbit energetic structure of silicon nano-materials plays a fundamental role in opening the way to high-performant devices. This is a special outcome as the origin of these powerful effects, i.e., the indirect band gap properties observed for silicon, was in the past considered one of main limitation of these materials [1–4].

**Conflicts of Interest:** The funders had no role in the design of the review; in the collection, in the analyses, nor in the interpretation of data; in the writing of the manuscript, nor in the decision to publish the results.
