Unique features of the nano-scale

Ten features that uniquely arise at the nano size range are discussed. These include those based on the obvious—the physically small size and concomitant large surface to volume ratio features. Importantly, they also include more subtle features that emerge at this scale including self-assembly possibilities, quantum confinement and tunneling, wave-particle duality, and plasmonic behavior. In addition, the list of ten encompasses very curious features that can manifest themselves at the nano-scale. These include enhanced friction and striction due to the Casimir “force” coming from quantum fluctuations as well as zero mass Dirac electrons which can arise from relativistic effects. The presence of Dirac electrons can result in very unusual material properties including ballistic charge transport, unusual Hall effects, enormously high carrier mobilities, and topologically dependent phases. The latter includes topological insulators, nano-materials characterized by having carriers with spin-momentum locking. A second type of nano-scale fluctuation behavior is also on the list of ten unique features of the nano size range: thermal fluctuations. These result in the statistical fluctuations around an average distribution becoming more observable thereby blurring the second law of thermodynamics at the nano-scale.