Room Temperature Dopant-Atom Quantum Dot Transistors in Silicon

Dopant atom quantum dot (QD) single-electron transistors (SETs) in Si provide a means to precisely control, even at room-temperature (RT), charge at the one-electron level. These devices exploit single-electron charging of ultra-small, ~1 nm scale QDs, formed by phosphorous dopant atoms within sub-10 nm point-contacts. RT single, and double QD electrical characteristics are presented. The devices are then used to investigate single-particle entropy at the Landauer limit, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{S}=\boldsymbol{k_{B}}\boldsymbol{T\ln 2}$</tex> and extract a single-particle <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{T}-\boldsymbol{S_{e}}$</tex> diagram. The results raise the potential for ultra-low power, few-nanometer scale, single electron, quantum nanoelectronics circuits.