Sandia Corporation

University of California

S James Allen

Michael C Wanke

Mark Lee

Eric A Shaner

Christopher Palmstrom

Alexander Kozhanov

A non-volatile logic gate, including a magnetic material having a shape induced magnetic anisotropy, wherein a shape of the magnetic material has a first vertex, a second vertex, and a third vertex and supports a single magnetic domain; regions of the magnetic material including a first input region adjacent the first vertex, a second input region adjacent the second vertex, and an output region adjacent a third vertex; the first input region for receiving a first logic input to the logic gate, the second input region for receiving a second logic input to the logic gate, and the output region for outputting at least one logic output of the logic gate; and the shape induced magnetic anisotropy determining at least part of a truth table for the logic gate, so that the logic gate produces the at least one logic output from the logic inputs using the shape.

Spin transfer torque triad for non-volatile logic gates

A direct detector for terahertz radiation comprises a grating-gated field-effect transistor with one or more quantum wells that provide a two-dimensional electron gas in the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating gate to near pinch-off greatly increases the detector's resonant response magnitude over prior QW FET detectors while maintaining frequency selectivity. The split-grating-gated QW FET shows a tunable resonant plasmon response to FIR radiation that makes possible an electrically sweepable spectrometer-on-a-chip with no moving mechanical optical parts. Further, the narrow spectral response and signal-to-noise are adequate for use of the split-grating-gated QW FET in a passive, multispectral terahertz imaging system. The detector can be operated in a photoconductive or a photovoltaic mode. Other embodiments include uniform front and back gates to independently vary the carrier densities in the channel region, a thinned substrate to increase bolometric responsivity, and a resistive shunt to connect the fingers of the grating gate in parallel and provide a uniform gate-channel voltage along the length of the channel to increase the responsivity and improve the spectral resolution.

Direct detector for terahertz radiation

A terahertz radiation mixer comprises a heterodyned field-effect transistor (FET) having a high electron mobility heterostructure that provides a gatable two-dimensional electron gas in the channel region of the FET. The mixer can operate in either a broadband pinch-off mode or a narrowband resonant plasmon mode by changing a grating gate bias of the FET. The mixer can beat an RF signal frequency against a local oscillator frequency to generate an intermediate frequency difference signal in the microwave region. The mixer can have a low local oscillator power requirement and a large intermediate frequency bandwidth. The terahertz radiation mixer is particularly useful for terahertz applications requiring high resolution.

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Santa Barbara, CA, United States of America

S James Allen