We outline a generic ratchet mechanism for creating directed spin-polarized currents in ac-driven double well or double dot structures by employing resonant spin transfer through the system engineered by local external magnetic fields. We show its applicability to semiconductor nanostructures by considering coherent transport through two coupled lateral quantum dots, where the energy levels of ...

Preface This report is a summary of the activities in the field of resonant tunneling device circuit design. (GMUD) during the first year of the Microelectronics Advanced Research Initiative projects ANSWERS (Autonomous Nanoelectronic Systems with Extended Replication and Signalling) and LOCOM (Logic Circuits with Reduced Complexity based on Devices with Higher Functionality). As part of the AN...

Realization of a robust nanotube-heterostructure tunneling transistors [Solid State Comm. 116, 569 (2000)] requires the difficult formation [Science 293, 76 (2001)] of a central nanoscale barrier separating a pair of outside metallic leads. Here I suggest an alternative surface-based assembly based on self-organization of one-dimensional metallic states on oxides and trapping well-resolved reso...

The effects of interface roughness scattering in a resonant-tunneling diode are examined with the selfconsistent Born and the multiple sequential scattering algorithm for various interface roughness correlation lengths. The effect of a self-consistent treatment of the scattering self-energies with the quantum charge and the electrostatic and exchange-correlation potentials is demonstrated. The ...

The nuclear fusion data for deuteron-triton resonance near 100 keV are found to be consistent with the selective resonant tunneling model. The feature of this selective resonant tunneling is the selectivity. It selects not only the energy level, but also the damping rate (nuclear reaction rate). When the Coulomb barrier is thin and low, the resonance selects the fast reaction channel; however, ...

Resonant photon tunneling was investigated experimentally in multilayer structures containing a high-contrast (TiO(2)/SiO(2)) Bragg mirror capped with a semitransparent gold film. Transmission via a fundamental cavity resonance was compared with transmission via the Tamm plasmon polariton resonance that appears at the interface between a metal film and a one-dimensional photonic bandgap structu...

-The resonant tunneling diode (RTD) has been applied to some kinds of microsensors and actuators .These sensors are based on the RTD with a frequency output. The oscillate circuit based on the RTD is the more importance factor on sensitivities and stability of the sensors .In this paper , two kinds of oscillator circuit are introduced, the principle function of the oscillator circuit is explain...

Insertion of a thin nonmagnetic copper Cu(001) layer between the tunnel barrier and the ferromagnetic electrode of a magnetic tunnel junction is shown to result in the oscillation of the tunnel magnetoresistance as a function of the Cu layer thickness. The effect is interpreted in terms of the formation of spin-polarized resonant tunneling. The amplitude of the oscillation is so large that even...

We have studied the polarized resolved photoluminescence of n-type GaAs/AlAs/GaAlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. Under resonant tunneling conditions, we have observed two emission lines attributed to neutral (X) and negatively charged excitons (X-). We have observed a voltage-controlled circular polarization degree from the quantum well emission...

We create a reservoir of hole traps in a resonant tunneling light emitting diode by etching the p-type contact into an array of nanometer scale pillars. In the off state, the charge reservoir keeps the light output extremely low, even at relatively high currents. The device can be switched on to produce light by raising the electron emitter past a confined electron state allowing holes to escap...