An ultrasmall single-electron transistor has been made by scaling the size of a fin field-effect transistor structure down to an ultimate limiting form, resulting in the reliable formation of a sub-5 nm Coulomb island. The charge stability data feature the first exhibition of three and a half clear Coulomb diamonds at 300 K, each showing a high peak-to-valley current ratio. Its charging energy is estimated to be more than one order magnitude larger than the thermal energy at room-temperature. The hybrid literal gate integrated by this single-electron transistor combined with a field-effect transistor displays >5 bit multiswitching behavior at 300 K with a large voltage swing of ～1 V

We report on transport measurement performed on a room-temperature-operating ultra-small Coulomb blockade devices with a silicon island of sub-5nm. The charge stability at 300K exhibits a substantial change in slopes and diagonal size of each successive Coulomb diamond, but remarkably its main feature persists even at low temperature down to 5.3K except for additional Coulomb peak splitting. This key feature of charge stability with additional fine structures of Coulomb peaks are successfully modeled by including the interplay between Coulomb interaction, valley splitting, and strong quantum confinement, which leads to several low-energy many-body excited states for each dot occupancy. These excited states become enhanced in the sub-5nm ultra-small scale and persist even at 300K in the form of cluster, leading to the substantial modulation of charge stability.

The aim of this study was to analyse the combined effect of melanocortin 4 receptor (MC4R) and high mobility group AT-hook 1 (HMGA1) polymorphisms on growth and fatness traits in Duroc pigs. No significant interaction was observed between MC4R and HMGA1 for back-fat traits. An additive mode of inheritance of both gene effects was found for average daily gain and lean meat content. Maximum mean differences from combined genotypic effects were over 2 mm for back fat, 70 g/day for average daily gain and 2% for lean meat content. Therefore, utilization of polymorphisms in both MC4R and HMGA1 for marker-assisted selection could result in an economic benefit to the pig industry.

A lateral gate-controlled double dot structure in Si has been fabricated for studying coupled two qubits. Nonequilibrium single-electron tunneling measurements at 1.4K show that the second Coulomb peak, associated with a two-electron occupation, splits into two side peaks, and that their separation displays a strong magnetic-field dependence for various interdot coupling constants. Moreover, for some fixed magnetic fields, the separation of the side peaks decays exponentially as a function of the interdot coupling. We attribute this behavior to electron spin exchange and spin swapping between singlet and triplet states in the coupled double dot in the presence of a magnetic field.

A Si-based coupled double dot has been studied for its application to two-qubit gate. The authors manipulated electron number of each dot by using its adjacent side gate and finally observed a honeycomb charge-stability pattern, demonstrating interdot capacitive coupling. From the honeycomb diagram the capacitance-related interdot coupling parameters were extracted. Moreover, a fine structure in a conductance trace near the triple point of the honeycomb, where the tunnel coupling is maximized, was measured for finite bias, and its dependence on the interdot coupling was attributed to the spin exchange between the two dots.