摘要:
A three-terminal quantum well device, which functions somewhat analogously to an MOS transistor. That is, the three terminals of the device can generally be considered as source, gate, and drain. An output contact is connected by tunneling to a number of parallel chains of quantum wells, each well being small enough that the energy levels in the well are quantized discretely. In each of these chains of wells, the second well is coupled to a common second conductor, and the first well is electronically coupled to a common first conductor.
摘要:
Optically pumped coupled quantum well devices are disclosed. The devices store bits as carrier packets in depressions in the conduction and/or valence band(s) of a single crystal; the band between the depressions is sloped in a common direction which provides unidirectionality. The carrier packets are shifted from depression to depression by optically exciting the carriers and relying on the arrangement of depressions and band slopes; the excitation is conveniently performed by laser illumination. The depressions may be sufficiently small to discretize the energy levels and thereby permit the partitioning of the depressions into groups with each group having depressions of substantially the same energy level structure. The carriers in depressions of one group can then be selectively excited by illumination with a laser or narrow band monochromatic incoherent light source tuned to the energy level structure; this allows multiphase operation of the shifting function.
摘要:
Quantum-coupled devices, wherein at least two closely adjacent potential wells, (e.g. islands of GaAs in an AlGaAs lattice) are made small enough that the energy levels of carriers within the wells are discretely quantized. This means that, when the bias between the wells is adjusted to align energy levels of the two wells, tunneling will occur very rapidly, whereas when energy levels are not aligned, tunneling will be greatly reduced. To provide output coupling from these quantum-well devices to macroscopic currents, the output from the quantum-well devices is injected into localized states close to an extremely small metal line (e.g. 200 Angstroms square in section). These trapped charged perturb the resistance of a metal line significantly, so that a conventional sense amplifier can be used for differential sensing between two such narrow metal lines, to provide macroscopic outputs.
摘要:
The present invention relates to uniform nanostructure biosensors and methods of calibrating the response of nanostructure biosensors. The invention overcomes device to device variability that has made quantitative detection difficult. The described biosensors have uniform characteristics that allow for more reliable comparison across devices. The methods of the invention comprise normalizing the initial current rate, as measured by the nanostructure biosensor following the addition of an analyte, to device characteristics of the biosensor. The device characteristics of the biosensor which can be used to normalize the response include baseline current and transconductance. Calibration of responses allows for the generation of calibration curves for use in all devices to quantitatively detect an analyte, without the need for individual device calibration.
摘要:
The systems and methods described herein include a sensor for suitable for sensing chemical and biological substances. The sensor comprises a semiconductor layer formed in or on a substrate and a channel having nano-scale dimensions formed in the semiconductor layer, where the structure creates an electrically conducting pathway between a first contact and a second contact on the semiconductor layer. In certain preferred embodiments, the nano-scale channel has a trapezoidal cross-section with an effective width and exposed lateral faces, where the effective width is selected to have same order of magnitude as a Debye length (LD) of the semiconductor material of which the semiconductor layer is formed.
摘要:
The present invention relates to a device and method for determining the presence of a specific compound in solution. The device includes a nanosensor having an electrically conducting pathway between at least a first and second contact. The device also includes a first receptor, suitable for binding a specific compound in the solution, attached to the nanosensor, and a second receptor also suitable for binding the specific compound while the specific compound is bound to the first receptor. The second receptor is attached to an enzyme added to the solution. When the solution having the second receptor is added to the device, and a second compound that is a substrate for the enzyme is subsequently added to the solution, a measured difference in an electrical property in the device before and after the application of the second compound is indicative of the presence of the specific compound in the solution.
摘要:
Molecular scale electronic devices are disclosed. Such devices include at least two conductive contacts, and a conductive path bridging the contacts. The conductive path is able to be written into a perturbed state by a voltage pulse, which can be of high or low conductivity, relative to an initial state. The conductive path comprises organic molecules including at least one electron-withdrawing group. Room temperature negative differential resistance is exhibited by the devices.
摘要:
A micromechanical sensor in which the impedance of a gap in a conductor, under tunnelling current conditions, is sensed to provide an indication of deflection in the conductor. This provides a new way to sense acceleration, strain, and other parameters which can be translated into a deflection.
摘要:
A resonant tunneling diode (30) with anode (40) and cathode (32) separated by binary short-period superlattice tunneling barriers (34,38) with a quantum well (36) between is disclosed. Enhancement and depletion mode diodes are disclosed.
摘要:
Quantum-coupled devices, wherein at least two closely adjacent potential wells, (e.g. islands of GaAs in an AlGaAs lattice) are made small enough that the energy levels of carriers within the wells are discretely quantized. This means that, when the bias between the wells is adjusted to align energy levels of the two wells, tunneling will occur very rapidly, whereas when energy levels are not aligned, tunneling will be greatly reduced. To provide output coupling from these quantum-well devices to macroscopic currents, the output from the quantum-well devices is injected into localized states close to an extremely small metal line (e.g. 200 Angstroms square in section). These trapped charged perturb the resistance of a metal line significantly, so that a conventional sense amplifier can be used for differential sensing between two such narrow metal lines, to provide macroscopic outputs.