Abstract: A fiber ring resonator having a relatively long loop of standard single-mode fiber with a short nanofiber segment. The evanescent mode of the nanofiber segment allows the cavity-enhanced field to interact with atoms in close proximity to the nanofiber surface.

Abstract: Quantum key distribution QKD systems and methods are provided that allow for QKD over distances not previously achievable. In one embodiment, the QKD system and method utilizes state discrimination techniques. In another embodiment, the QKD system and method utilizes amplifiers and unitary transformations to extend the range over which QKD can be achieved. The QKD systems and methods of the present invention can be used to implement secure quantum communications systems.

Abstract: Techniques are provided for placing atoms inside an appropriate nanocavity for enhancing two-photon absorption and quantum information processing based on the Zeno effect. Techniques for fabricating suitable nanocavities include: 1) a short length of optical fiber polished on the ends with the ends coated to form suitable mirrors; 2) a continuous length of fiber with the equivalent of mirrors being formed within the fiber using Bragg gratings; 3) a single filament of glass (such as fused silica) being suspended between two mirrors (without any cladding) and surrounded by an atomic vapor, solid, or liquid; 4) a small glass sphere (such as fused silica) that has been melted on the end of an optical fiber; and 5) a small toroid (ring) of glass bent in a circle surrounded by suitable atoms.

Abstract: An optical switch and optical storage loop are used as the basis of a single-photon source and a quantum memory for photonic qubits. To operate as a single-photon source, the techniques include a source of a pair of photons, such as a parametric down-conversion crystal, which is known to emit photons in pairs. The detection of one member of the pair activates the switch, which re-routes the other member into the storage loop. The stored photon is then known to be circulating in the loop, and can be switched out of the loop at a later time chosen by the user, providing a single photon for potential use in a variety of quantum information processing applications. To operate as a quantum memory for photonic qubits, a single-photon in an arbitrary initial polarization state is coherently stored in the loop, and coherently switched out of the loop when needed.

Abstract: Techniques are provided that use the quantum Zeno effect to implement practical devices that use single photons as the qubits for quantum information processing. In the quantum Zeno effect, a randomly-occurring event is suppressed by frequent measurements to determine whether the event has occurred. The same results can be obtained by using atoms or molecules or ions to react to the occurrence of the event. Techniques include directing one or more input qubits onto a device and applying a quantum Zeno effect in the device. The quantum Zeno effect is applied by consuming one or more photons in the device under conditions in which photons, that would otherwise be output by the device, do not represent a result of a particular quantum information processing operation. Devices implemented using the quantum Zeno effect can operate with low error rates without the need for high efficiency detectors and large number of ancilla.

Abstract: A semiconductor structure includes a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material, and a monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material. A composite transistor includes a first transistor having first active regions formed in the monocrystalline silicon substrate, a second transistor having second active regions formed in the monocrystalline compound semiconductor material, and a mode control terminal for controlling the first transistor and the second transistor.

Abstract: An integrated circuit for intermediate impedance matching and stabilization of high power devices is disclosed. High quality epitaxial layers of monocrystalline materials grown over monocrystalline substrates enables the formation of impedance matching and stability circuits to be placed on the same substrate as the active device. Additionally, by using the manifolds of the active to form plates of a capacitor, an impedance matching network of series inductance and shunt capacitor can be compactly fabricated for increasing the output impedance to intermediate levels. The manifolds of the active device are also used to form capacitors to provide stability to high power active devices.

Abstract: A semiconductor structure includes a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material, and a monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material. A composite transistor includes a first transistor having first active regions formed in the monocrystalline silicon substrate, a second transistor having second active regions formed in the monocrystalline compound semiconductor material, and a mode control terminal for controlling the first transistor and the second transistor.

Abstract: Various semiconductor device structures that include an inductor or balun can be formed using a semiconductor structure having a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material; and a monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material, and/or other types of material such as metals and non-metals.

Abstract: Various semiconductor device structures that include one or more capacitors can be formed using a semiconductor structure having a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material; and a monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material, and/or other types of material such as metals and non-metals.

Abstract: High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline material layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. In addition, formation of a compliant substrate may include utilizing surfactant enhanced epitaxy, epitaxial growth of single crystal silicon onto single crystal oxide, and epitaxial growth of Zintl phase materials.

Abstract: A semiconductor structure for a high frequency monolithic switch matrix includes a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material, a monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material, and a high frequency semiconductor integrated formed in and over the monocrystalline compound semiconductor material having one or more input ports and one or more output ports. The high frequency semiconductor integrated circuit also includes a high frequency switch circuit that is electrically coupled to a switch driver control circuit that is fabricated on the monocrystalline compound semiconductor material and which provides the DC signals required to control the high frequency circuit.

Abstract: A semiconductor structure for isolating high frequency circuitry includes a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material, a monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material, a plurality of high frequency circuits formed in and over the monocrystalline compound semiconductor material, and at least one embedded isolation wall lying within the compound semiconductor material to isolate the high frequency circuits.

Abstract: A semiconductor structure for integrated control of an active subcircuit includes a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material, a monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material, the active subcircuit in the monocrystalline compound semiconductor material, and a bias subcircuit in the monocrystalline silicon substrate and electrically coupled to the active subcircuit to bias the active subcircuit.

Abstract: High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline material layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. Radio frequency, optical, logic and other circuits in both silicon and compound semiconductor materials may be combined and interconnected in a single semiconductor structure.

Abstract: Microelectromechanical (MEMS) devices are integrated with high frequency devices on a monolithic substrate or wafer. High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. MEMS devices, such as a switch, a variable capacitance device or a temperature control structure, are formed in the base monocrystalline substrate. High frequency devices, such as transistors or diodes, are formed in the overlaying layer of monocrystalline materials.

Abstract: An integrated circuit for intermediate impedance matching and stabilization of high power devices is disclosed. High quality epitaxial layers of monocrystalline materials grown over monocrystalline substrates enables the formation of impedance matching and stability circuits to be placed on the same substrate as the active device. Additionally, by using the manifolds of the active to form plates of a capacitor, an impedance matching network of series inductance and shunt capacitor can be compactly fabricated for increasing the output impedance to intermediate levels. The manifolds of the active device are also used to form capacitors to provide stability to high power active devices.

Abstract: A semiconductor structure with selective doping includes a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material, at least one monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material, and a transistor in the at least one monocrystalline compound semiconductor material and including active regions having different conductivity levels under substantially identical bias conditions.

Abstract: High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline material layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. In addition, formation of a compliant substrate may include utilizing surfactant enhanced epitaxy, epitaxial growth of single crystal silicon onto single crystal oxide, and epitaxial growth of Zintl phase materials.

Abstract: High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer of silicon oxide. In addition, formation of a compliant substrate may include utilizing surfactant enhanced epitaxy, epitaxial growth of single crystal silicon onto single crystal oxide, and epitaxial growth of Zintl phase materials. A thermo-electric device is integrated into the semiconductor structure.