Patent Application
20200350409
Not applicable.
Not applicable.
The discovery of a single sheet of carbon atoms has led to the development of two-dimensional (2D) materials beyond graphene, which show superior electrical, optical, mechanical, and chemical properties and therefore has the potential to revolutionize electronics. What is characteristic of 2D materials is that they are composed of layers of atoms that form strong covalent bonds within each layer without dangling bonds. Meanwhile, the interlayer bonding is solely due to the van der Waals force, which is much weaker than the covalent bond so that an individual 2D layer of atoms could be easily separated.
Thus, many elemental chains (EC) such as Se, Al, Ba, Bi, Sb, and Sr have been theoretically studied for the band structure, and it is predicted that some of them might exist under extreme conditions, such as high pressure. The success of STM development has enabled the manipulation of single atoms to form ordered linear or 2D arrays. This has triggered theoretical investigations using artificially formed 1D atomic chains to build electronic devices, which are seen as the ultimate building blocks for transistors.
In one embodiment, the present invention provides a method that enables a full suite of “atom circuits and devices” based on switching electron waves between atom chains as shown in
In other embodiments, the present invention provides methods that create chains of atoms.
In other embodiments, the present invention provides methods that create isolated single chains or multiple chains that are controllably coupled to each other.
In other embodiments, the chains may be one-dimensional chains of atoms, the atoms form strong covalent bonds with no dangling bonds except at both ends of the chain and the chains are bonded together through van der Waals force.
In other embodiments, the present invention provides methods that create chains of atoms to form regular integrated circuits or quantum integrated circuits.
In other embodiments, the chains host quantum dots functioning as single photon sources and detectors and as electron spin qubits.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
In the drawings, which are not necessarily drawn to scale, like numerals may describe substantially similar components throughout the several views. Like numerals having different letter suffixes may represent different instances of substantially similar components. The drawings illustrate generally, by way of example, but not by way of limitation, a detailed description of certain embodiments discussed in the present document.
Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed method, structure or system. Further, the terms and phrases used herein are not intended to be limiting, but rather to provide an understandable description of the invention.
One element that may be formed into elemental chains (EC) is Si which has semiconductor properties as shown in
The interchain bonding (van der Waals) is much weaker than the intrachain bonding (covalent). This weak bonding may be utilized in the very early stage of van der Waals epitaxy to grow Se on Te to achieve a high-quality large lattice mismatch growth.
Accordingly, for a preferred embodiment of the present invention, 1D elemental chain materials may be formed, including single Se and Te atomic chains, as well as heterostructures formed by them. These structures may be used as basic building blocks to construct nano-electronics and quantum circuits.
To obtain single atomic chains of Se and Te, two approaches may be used. A top-down approach may be used to separate a single sheet of material such as graphene to separate single atomic chains. A bottom-up approach may also be used to perform self-assembly of atomic chain growth on high-index crystal substrates.
When Se atoms are forced to align in 1D, they tend to spontaneously form an atomic chain with two neighbor atoms connected with a covalent bond. Such a structure is thermodynamically stable. Based on this mechanism, the present invention, for a preferred embodiment, uses molecular beam epitaxy (MBE) to grow large area atomic chains 400-402, which may be comprised of Se and/or Te, on a high index semiconductor substrate 410 as shown in
The steps of the substrate provide a natural template to guide the alignment of the atoms. The chains will form along valleys as it will take much more energy to form the bond laterally across the valleys 430-432 and peaks 440-442.
The atoms collect at terrace edges 450-452 to lower the surface energy. Therefore, stable, well-aligned, and long atomic chains could be formed. The spacing between the steps will be tuned by growing on different high index or cut substrates. MBE growth is used as it provides atomic layer resolution deposition capability, in-situ monitoring (RHEED), UHV environment, and additional control to form high index surfaces.
In other embodiments of the present invention, both Se and Te chains may be grown. Se is more anisotropic (1D-like) than Te, but Se has a much lower melting point than Te which may limit the mobility of Se atoms on growth substrates. Other embodiments may grow chains on a variety of different substrates, from high-index, reconstructed GaAs surfaces to miscut quartz and sapphire.
In other aspects, the present invention may be used to construct simple devices. One such device is a single atomic chain MOSFET. The atomic chain may be transferred to a SiO2 substrate followed by depositing dielectric material and metal contact to form a simple MOSFET. This will provide a baseline for the device characteristics. Other embodiments may also directly grow the atomic chain on miscut quartz wafers to develop in-situ fully depleted MOSFET architecture (similar to SOI).
A single chain with two electrodes will also work as optoelectronic devices such as photoconductors and diodes. By choosing different metals, the structure may also work as a Schottky diode for photodetection. An external electric field may be used to form a PN junction along the chain so that the structure could be configured as a light emitting diode. A bipolar injection may be obtained by directly engineering the metal work functions rather than using doping.
As shown in
As shown in
As shown in
In yet other embodiments, a “quantum wire” may be created by using high index quartz wafers along with the single chain structure described above. The single chain structure is an ideal platform for creating single photon emitters and single photon detectors.
In yet other embodiments, the present invention may be used to form integrated “Quantum Circuits” by assembling devices based on the coupling of electron waves between atomic chain structures. For example, linear, ring, and other chain structures form the basic building blocks of quantum circuits as shown in
In other embodiments, the present invention provides a semiconductor device comprised of one or more one-dimensional chains of atoms, the atoms form strong covalent bonds with no dangling bonds except at both ends of the chain, and the chains are bonded together through van der Waals force in an ordered nature to form a single crystal. The device may have a helical structure of atomic chains that require electrons to twist as they travel along the chain to produce unique magneto transport signatures, strongly affect electron spin states in the chains, and generate topological end modes. In yet other embodiments, only one direction is allowed by the helicity of the chain which will generate a magnetic field along the chain that creates a unique type of spin-orbit interaction. In other embodiments, quantum dots may be defined within the chain to create single photon sources and detectors, as well as electron spin qubits that may have enhanced coherence by engineering the nuclear isotopes of Se and Te atoms forming the chain. In other aspects, an external electrical field may be used to form a PN junction along the chain, so that the structure may be configured as a light emitting diode.
In other embodiments, the present invention provides a method wherein the atomic chain is transferred to a SiO2 substrate followed by depositing dielectric material and a metal contact to form a MOSFET. In other applications, a single chain with two electrodes may be configured as a photoconductor by choosing different metals. The structure may also work as a Schottky diode for photodetection.
In still further embodiments, the present invention provides a semiconductor device comprised of one or more one-dimensional chains of atoms, the atoms form strong covalent bonds with no dangling bonds except at both ends of the chain and the chains are bonded together through van der Waals force in an ordered nature to form regular integrated circuits as well as quantum integrated circuits by placing chains in close proximity to qubits, quantum sensors, and quantum nanophotonic devices.
In other embodiments, the chains of the semiconductor device have no dangling bonds except at both ends of the chain and the chains are bonded together through van der Waals force in an ordered nature to form a sensor. The chains may also be used to sensors for gasses, chemicals, temperature, pressure, and biomolecules (DNA, viruses, proteins). In other aspects, the atomic chains replace nanowires as sensors because of a 100× larger surface to volume ratio. The chains may also be used as pressure sensors as a result of having spiral structures and highly flexible mechanical properties.
While the foregoing written description enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The disclosure should therefore not be limited by the above described embodiments, methods, and examples, but by all embodiments and methods within the scope and spirit of the disclosure.
This application is a divisional of U.S. application Ser. No. 15/910,789 filed on Mar. 2, 2018, which claims the benefit of U.S. Provisional Application No. 62/466,074 filed Mar. 2, 2017, both of which are herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62466074 | Mar 2017 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15910789 | Mar 2018 | US |
| Child | 16931246 | US |
