A two-dimensional ON/OFF switching device based on anisotropic interactions of atomic quantum dots on Si(100):H

Abstract

Controlling the properties of quantum dots at the atomic scale, such as dangling bonds, is a general motivation as they allow studying various nanoscale processes including atomic switches, charge storage, or low binding energy state interactions. Adjusting the coupling of individual silicon dangling bonds to form a 2D device having a defined function remains a challenge. Here, we exploit the anisotropic interactions between silicon dangling bonds on n-type doped Si(100):H surface to tune their hybridization. This process arises from interactions between the subsurface silicon network and dangling bonds inducing a combination of Jahn–Teller distortions and local charge ordering. A three-pointed star-shaped device prototype is designed. By changing the charge state of this device, its electronic properties are shown to switch reversibly from an ON to an OFF state via local change of its central gap. Our results provide a playground for the study of quantum information at the nanoscale.

Electrostatic Landscape of a Hydrogen-Terminated Silicon Surface Probed by a Moveable Quantum Dot

“…The DB-DB analysis also allowed extraction of an experimentally determined distance where the DB pair occupation changes, confirming less direct measures and with important implications for DB-based device applications. [5][6][7][8] Our approach of placing the single atom quantum dot directly on the surface of interest provides the highest spatial resolution of lateral potential variations as measured by scanning quantum dot microscopy to date. Direct comparison of our observations with complementary KPFM maps highlights the impact that charged species have on the electrostatic landscape of a surface.…”

“…DBs can hold zero, one, or two electrons resulting in a positive, neutral, or negative charge state respectively. 5,8,25,26 In correspondence with these three charge states, there exist two distinct charge transition levels, (+/0) and (0/-), the specific energies of which are sensitive to their local electrostatic environment. 6,24,25 Other articles have detailed the precise patterning [27][28][29] and erasing 30,31 of DBs on H-Si (see Methods), which we employ here to progressively march a probing DB through the vicinity of charged species (e.g.…”

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

“…Novel approaches to advance integrated circuitry beyond CMOS have focused on atom scale structures and their reliable fabrication [1]. Hydrogen-terminated silicon (H-Si) surfaces are one such versatile platform for the patterning and operation of atom scale devices including qubits [2,3] and single electron transistors [4,5] made from atomically precise implanted donor atoms near the H-Si surface, and logic structures using fabricated silicon dangling bonds [6][7][8]. In many cases the structures' functional elements are comprised of a few or even single atoms.…”

Two-Dimensional Functionalized Ultrathin Semi-Insulating CaF2 Layer on the Si(100) Surface at a Low Temperature for Molecular Electronic Decoupling

“…At lower scale, the approach is different since current leakage can be exploited for specific tunnel transport in molecular scale devices 12,13 . In the context of molecular electronics, ultra-thin insulating layers made of a few atomic crystallographic scale coats have already been largely investigated.…”