Abstract: A photodetector for the detection of radiated electromagnetic energy includes at least one bolometer nanowire disposed at least partially within a photon trap. The at least one nanowire has at least one blackened surface. The blackened surface is configured to absorb radiated electromagnetic energy ranging from far-infrared light to visible light.

Abstract: A photodetector for the detection of radiated electromagnetic energy includes at least one bolometer nanowire disposed at least partially within a photon trap. The at least one nanowire has at least one blackened surface. The blackened surface is configured to absorb radiated electromagnetic energy ranging from far-infrared light to visible light.

Abstract: A photodiode includes a first electrode, a second electrode, and a nanowire comprising a semiconductor core and a semiconductor shell. The nanowire has a first end and a second end, the first end being in electrical contact with the first electrode and the second end being in contact with the second electrode.

Abstract: Devices such as transistors, amplifiers, frequency multipliers, and square-law detectors use injection of spin-polarized electrons from one magnetic region, into another through a control region and spin precession of injected electrons in a magnetic field induced by current in a nanowire. In one configuration, the nanowire is also one of the magnetic regions and the control region is a semiconductor region between the magnetic nanowire and the other magnetic region. Alternatively, the nanowire is insulated from the control region and the two separate magnetic regions. The relative magnetizations of the magnetic regions can be selected to achieve desired device properties. A first voltage applied between one magnetic region and the other magnetic nanowire or region causes injection of spin-polarized electrons through the control region, and a second voltage applied between the ends of the nanowire causes a current and a magnetic field that rotates electron spins to control device conductivity.

Abstract: An efficient spin polarizer in nonmagnetic semiconductors is provided. Previous spin injection devices suffered from very low efficiency (less than 35%) into semiconductors. An efficient spin polarizer is provided which is based on ferromagnetic-semiconductor heterostructures and ensures spin polarization of electrons in nonmagnetic semiconductors close to 100% near the ferromagnetic-semiconductor junctions at wide temperature intervals ranging from very low temperatures to room temperatures even in the case when spin polarization of electrons in the ferromagnetic layer is relatively low.

Abstract: Spin-polarized electrons can be efficiently extracted from an n-doped semiconductor layer (n-S) by forming a modified Schottky contact with a ferromagnetic material (FM) and a ?-doped layer at an interface under forward bias voltage conditions. Due to spin-selection property of the FM-S junction, spin-polarized carriers appear in the n-doped semiconductor layer near the FM-S interface. If a FM-n-n?-p heterostructure is formed, where the n? region is a narrower gap semiconductor, polarized electrons from the n-S region and holes from the p-S region can diffuse into the n?-S region under the influence of independent voltages applied between the FM and n? regions and the n? and p regions. The polarized electrons and holes recombine in the n?-S region and produce polarized light. The polarization can be controlled and modulated by controlling the applied voltages.

Abstract: Devices such as transistors, amplifiers, frequency multipliers, and square-law detectors use injection of spin-polarized electrons from one magnetic region, into another through a control region and spin precession of injected electrons in a magnetic field induced by current in a nanowire. In one configuration, the nanowire is also one of the magnetic regions and the control region is a semiconductor region between the magnetic nanowire and the other magnetic region. Alternatively, the nanowire is insulated from the control region and the two separate magnetic regions. The relative magnetizations of the magnetic regions can be selected to achieve desired device properties. A first voltage applied between one magnetic region and the other magnetic nanowire or region causes injection of spin-polarized electrons through the control region, and a second voltage applied between the ends of the nanowire causes a current and a magnetic field that rotates electron spins to control device conductivity.

Abstract: An apparatus for controlling propagation of incident electromagnetic radiation is described, comprising a composite material having electromagnetically reactive cells of small dimension relative to a wavelength of the incident electromagnetic radiation. Each electromagnetically reactive cell comprises a metallic element and a substrate. An electron population within the substrate near the metallic element of at least one of the electromagnetically reactive cells is temporally controllable to allow temporal control of an associated effective refractive index encountered by the incident electromagnetic radiation while propagating through said composite material.

Abstract: A magnetic sensor using efficient injection of spin polarized electrons at room temperature can be fabricated by forming a semiconductor layer sandwiched between ferromagnets and forming ?-doped layers between the semiconductor layer and the ferromagnets. A sensing method applies a magnetic field to be measured to the semiconductor layer and observes the conductivity of the sensor. The sensing techniques can achieve high magneto-sensitivity and very high operating speed, which in turn provides ultra fast and sensitive magnetic sensors.

Abstract: A device and method for hetero laser and light-emission of high polarization radiation. Previous light emitting devices suffered from very low degree of the radiation polarization. A hetero laser and light emitting device with a semiconductor layer sandwiched between ?-doped layers and ferromagnets allows for highly polarized light to be emitted.

Abstract: Ultrafast square-law detectors amplify electric currents and electromagnetic waves with frequencies on the order of 100 GHz or more. The detectors use injection of spin-polarized electrons from a magnetic film or region into another magnetic film or region through a thin semiconductor control region. A signal current flowing through a conductive nanowire induces a magnetic field causing precession of electron spin injected inside the semiconductor layer and thereby changing the conductivity of the detector. With the magnetizations of the magnetic regions being parallel or antiparallel to each other, the resulting spin injection current includes a term proportional to the square of the signal current so that the detector behaves as a square-law detector. Such square-law detectors are magnetic-semiconductor heterostructures and can operate as a frequency doubler for millimeter electromagnetic waves.

Abstract: Ultrafast solid state amplifiers of electrical current, including power amplification devices, use injection of spin-polarized electrons from a magnetic region into another magnetic region through a semiconductor control region and electron spin precession inside the control region induced by a magnetic field resulting from a current flowing through a conductive nanowire. The amplifiers may include magnet-semiconductor-magnet heterostructures and are able to operate on electric currents and electromagnetic waves having frequencies up to 100 GHz or more.

Abstract: A magnetic sensor based on efficient spin injection of spin-polarized electrons from ferromagnets into semiconductors and rotation of electron spin under a magnetic field. Previous spin injection structures suffered from very low efficiency (less than 5). A spin injection device with a semiconductor layer sandwiched between &dgr;-doped layers and ferromagnets allows for very high efficient (close to 100%) spin polarization to be achieved at room temperature, and allows for high magneto-sensitivity and very high operating speed, which in turn allows devising ultra fast and sensitive magnetic sensors.

Abstract: A magnetic sensor using efficient injection of spin polarized electrons at room temperature can be fabricated by forming a semiconductor layer sandwiched between ferromagnets and forming &dgr;-doped layers between the semiconductor layer and the ferromagnets. A sensing method applies a magnetic field to be measured to the semiconductor layer and observes the conductivity of the sensor. The sensing techniques can achieve high magneto-sensitivity and very high operating speed, which in turn provides ultra fast and sensitive magnetic sensors.

Abstract: A device and method for hetero laser and light-emission of high polarization radiation. Previous light emitting devices suffered from very low degree of the radiation polarization. A hetero laser and light emitting device with a semiconductor layer sandwiched between &dgr;-doped layers and ferromagnets allows for highly polarized light to be emitted.

Abstract: An efficient spin injection into semiconductors. Previous spin injection devices suffered from very low efficiency (less than 2% at room temperature) into semiconductors. A spin injection device with a &dgr;-doped layer placed between a ferromagnetic layer and a semiconductor allows for very high efficient (close to 100%) spin injection to be achieved at room temperature.

Abstract: An efficient spin injection into semiconductors. Previous spin injection devices suffered from very low efficiency (less than 2% at room temperature) into semiconductors. A spin injection device with a &dgr;-doped layer placed between a ferromagnetic layer and a semiconductor allows for very high efficient (close to 100%) spin injection to be achieved at room temperature.