摘要:
A NERS-active structure is disclosed that includes at least one heterostructure nanowire. The at least one heterostructure nanowire may include alternating segments of an NERS-inactive material and a NERS-active material in an axial direction. Alternatively, the alternating segments may be of an NERS-inactive material and a material capable of attracting nanoparticles of a NERS-active material. In yet another alternative, the heterostructure nanowire may include a core with alternating coatings of an NERS-inactive material and a NERS-active material in a radial direction. A NERS system is also disclosed that includes a NERS-active structure. Also disclosed are methods for forming a NERS-active structure and methods for performing NERS with NERS-active structures.
摘要:
A patterned array of metallic nanostructures and fabrication thereof is described. A plurality of nanowires is grown on a substrate, the plurality of nanowires being laterally arranged on the substrate in a predetermined array pattern. The plurality of nanowires is coated with a metal to generate a plurality of metal-coated nanowires. Vacancies between the metal-coated nanowires are filled in with a sacrificial material for stabilization, and the metal-coated nanowires are planarized. The sacrificial material is removed, the patterned array of metallic nanostructures being formed by the plurality of planarized metal-coated nanowires.
摘要:
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.
摘要:
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 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.
摘要:
An optical resonator configured to be tuned using piezoelectric actuation, includes a core, the core being configured to transmit light; a piezoelectric layer; a first electrode and a second electrode. The piezoelectric layer is interposed between the first electrode and the second electrode. A voltage difference across the first and second electrodes alters a geometric dimension of the piezoelectric layer such that physical force is applied to the core and a resonant optical frequency of the resonator is changed. A method of utilizing mechanical stress to tune an optical resonator includes applying physical force to the resonator by subjecting a piezoelectric material to an electric field, the physical force changing a resonant frequency of the resonator.
摘要:
A surface enhanced Raman spectroscopy (SERS) apparatus employs a nanorod in an indentation in a surface of a substrate. The SERS apparatus includes the nanorod having a tip at a free end opposite to an end of the nanorod that is supported by the substrate indentation. The indentation has a tapered profile and supports the nanorod at a bottom of the indentation. The free end of the nanorod extends away from the indentation bottom. The SERS apparatus further includes a Raman-active material at a surface of one or both of the nanorod and the indentation. The indentation and the nanorod facilitate one or both of production and detection of a Raman scattering signal emitted by an analyte in a vicinity of the nanorod and indentation.
摘要:
A memcapacitor device (100) includes a first electrode (104) and a second electrode (106) and a memcapacitive matrix (102) interposed between the first electrode (104) and the second electrode (106). Mobile dopants (111) are contained within the memcapacitive matrix (102) and are repositioned within the memcapacitive matrix (102) by the application of a programming voltage (126) across the first electrode (104) and second electrode (106) to alter the capacitance of the memcapacitor (100). A method for utilizing a memcapacitive device (100) includes applying a programming voltage (126) across a memcapacitive matrix (102) such that mobile ions (111) contained within a memcapacitive matrix (102) are redistributed and alter a capacitance of the memcapacitive device (100), then removing the programming voltage (126) and applying a reading voltage to sense the capacitance of the memcapacitive device (100).
摘要:
Methods and apparatus characterized by distinct operating modes are provided. A thin graphite material defined by graphene layers is supported on a silicon substrate. The graphite material is defined by edge sites at the interface with the silicon. The graphite material is characterized by electrical superconductive-like behavior at room-temperatures while electrical current flows there through in a first direction. The graphite material is further characterized by a transition to Ohmic behavior while electrical current flows there through in a second direction opposite to the first. Devices exhibiting diode-like behavior can be formed accordingly.
摘要:
An electromagnetic resonance device includes an input reflector, an output reflector, and a periodic dielectric medium (PDM) disposed between the input reflector and the output reflector. The input reflector and output reflector are configured to be reflective to radiation having a wavelength of interest. The PDM includes a periodic structure having a dielectric periodicity between a first surface and a second surface. The dielectric periodicity is configured with a negative refraction for the wavelength of interest. A first radiation is reflected by the input reflector toward the first surface of the PDM, passes through the PDM, and is focused on the output reflector as a second radiation. The second radiation is reflected by the output reflector toward the second surface of the PDM, passes through the PDM, and is focused on the input reflector as the first radiation.
摘要:
Methods and apparatus pertaining to magnetically sensitive devices are provided. A device includes a graphite containing-material (GCM) supported in contact with respective pairs of electrodes. The GCM is subject to a magnetic field. Various levels of electric current are driven through the GCM, while corresponding voltage measurements are taken. Resulting current-versus-voltage data pairs are compared to calibration data for the device. Magnetic field intensities, operating states of the device or other determinations can be made according to the comparison.