Abstract:
This application concerns quantum computing, and in particular to structures and mechanisms for providing topologically protected quantum computation. In certain embodiments, a magnetic tunnel barrier is controlled that separates Majorona zero modes ("MZMs") from an edge area (e.g., a gapless edge) of a quantum spin hall system. In particular implementations, the magnetic tunnel barrier is formed from a pair of magnetic insulators whose magnetization is held constant, and the magnetic tunnel barrier is tuned by controlling a gate controlling the electron density around the magnetic insulator in the QSH plane, thereby forming a quantum dot. And, in some implementations, a state of the quantum dot is read out (e.g., using a charge sensor as disclosed herein).
Abstract:
A method for preparing semiconductor nanocrystals comprising adding a precursor mixture comprising one or more cation precursors, one or more anion precursors, and one or more amines to a ligand mixture including one or more acids, one or more phenol compounds, and a solvent to form a reaction mixture, wherein the molar ratio of (the one or more phenol compounds plus the one or more acids plus the one or more amine compounds) to the one or more cations initially included in the reaction mixture is greater than or equal to about 6, and heating the reaction mixture at a temperature and for a period of time sufficient to produce semiconductor nanocrystals having a predetermined composition. Methods for forming a buffer layer and/or an overcoating layer there over are also disclosed. Semiconductor nanocrystals may include one or more Group IMA and one or more Group VA elements.
Abstract:
Plasmonic nanoscale devices with increased emissions are disclosed. Highly concentrated fields of plasmonic nanocavities are integrated with a core to alter the excited-state optical processes. A plasmonic device (e.g., a nanowire) is created using a direct or indirect bandgap material core, an interlayer and a metallic shell.
Abstract:
Certain embodiments disclosed herein relate to the formation of multi-component oxide heterostructures (MCOH) using surface nucleation to pattern the atomic layer deposition (ALD) of perovskite material followed by patterned etch and metallization to produce ultra-high density MCOH nano-electronic devices. Applications include ultra-high density MCOH memory and logic, as well as electronic functionality based on single electrons, for example a novel flash memory cell Floating-Gate (FG) transistor with LaAlO3 as a gate tunneling dielectric. Other types of memoiy devices (DIMMS. DRAM, and DDR) made with patterned ALD Of LaAlO3 as a gate dielectric are also possible.
Abstract:
The present invention provides templating methods for replicating patterned metal films from a template substrate such as for use in plasmonic devices and metamaterials. Advantageously, the template substrate is reusable and can provide plural copies of the structure of the template substrate. Because high-quality substrates that are inherently smooth and flat are available, patterned metal films in accordance with the present invention can advantageously provide surfaces that replicate the surface characteristics of the template substrate both in the patterned regions and in the unpatterned regions.
Abstract:
An electrical device using metal nanocones and a method for handling nanocones. The electrical device includes a conductive element having a metallic spherical section, a metallic conical section integrally connected to the spherical end, and a tip section integrally connected to the conical section and narrowing in width as the tip section extends from the conical section. The electrical device includes a first electrode connected to the metallic spherical section, a second electrode disposed proximate the tip section, and a gate electrode applying an electric field to the metallic conical section and the tip section. The method includes filling a first surface containing nanocones with a polymerizable medium, polymerizing the medium to encapsulate the nanocones in the medium, and removing the polymerized medium from the first surface.
Abstract:
One or more quantum dots are used to control current flow in a transistor. Instead of being disposed in a channel between source and drain, the quantum dot (or dots) are vertically separated from the source and drain by an insulating layer. Current can tunnel between the source/drain electrodes and the quantum dot (or dots) by tunneling through the insulating layer. Quantum dot energy levels can be controlled with one or more gate electrodes capacitively coupled to some or all of the quantum dot(s). Current can flow between source and drain if a quantum dot energy level is aligned with the energy of incident tunneling electrons. Current flow between source and drain is inhibited if no quantum dot energy level is aligned with the energy of incident tunneling electrons. Here energy level alignment is understood to have a margin of about the thermal energy (e.g., 26 meV at room temperature).
Abstract:
A quantum device is provided that includes controllably quantum mechanically coupled dangling bonds extending from a surface of a semiconductor material. Each of the controllably quantum mechanically coupled dangling bonds has a separation of at least one atom of the semiconductor material. At least one electrode is provided for selectively modifying an electronic state of the controllably quantum mechanically coupled dangling bonds. By providing at least one additional electron within the controllably quantum mechanically coupled dangling bonds with the proviso that there exists at least one unoccupied dangling bond for each one additional electron present, the inventive device is operable at least to 293 degrees Kelvin and is largely immune to stray electrostatic perturbations. Room temperature operable quantum cellular automata and qubits are constructed thereform.
Abstract:
Die Erfindung betrifft ein Drei- oder Mehrtorbauelement auf der Basis des quantenmechanischen Tunneleffekts. Das Bauelement umfasst mindestens zwei durch eine für Elektronen durchtunnelbare Lücke beabstandete Tunnelelektroden auf einem Substrat. Erfindungsgemäß weist das Bauelement Mittel zur Beaufschlagung der Lücke mit einem derartigen elektrischen Feld auf, dass der Weg eines zwischen den Tunnelelektroden tunnelnden Elektrons infolge Ablenkung durch dieses Feld verlängert wird. Es können auch allgemein Mittel zur Beaufschlagung der Lücke mit einem elektrischen Feld vorgesehen sein, das eine Feldkomponente enthält, welche senkrecht zur Richtung des Tunnelstroms zwischen den Tunnelelektroden und parallel zum Substrat verläuft. Da der Tunnelstrom zwischen den Tunnelektroden exponentiell von der Wegstrecke abhängt, die die Elektronen in der Lücke zurücklegen, hat ein derartiges elektrisches Feld einen hohen Durchgriff auf die Tunnelwahrscheinlichkeit und damit auf den zu steuernden Tunnelstrom. Ein solches Bauelement kann etwa als sehr schnell schaltender Transistor mit hoher Verstärkung wirken und muss dabei nicht halbleitend sein.