The conductance of atomic scale filaments with three and seven Cu atoms in a-alumina are calculated using ab initio density functional theory. We find that the filament with 3 Cu atoms is sufficient to increase the conductance of 1.3 nm thick alumina film by more than 10 times in linear response. As the applied voltage increases, the current quickly saturates and differential resistance becomes...

Negative differential resistance has been observed from InAs homojunction light-emitting diodes grown using liquid-phase epitaxy at 455 °C. The devices were characterized using current–voltage sI–Vd and electroluminescence spectroscopy measurements to obtain information about structure defects in InAs. Two distinct negative differential resistance regions were observed in the forward bias I–V c...

The work of the last two decades on RTDs has been dominated by the needs of semiconductor heterostructure devices for high frequency operation and high speed applications. The fast transit time of the quantum effect involved in the conduction mechanism and the exhibited negative differential resistance have motivated these extensive efforts. The development of the band-gap engineering has opene...

many cell lines, when cultured under proper conditions, can form three dimensionalstructures called multicellular spheroids. these spheroids resemble in vivo tumor models in severalaspects. therefore, studying growth characteristics and behavior of spheroids is beneficial inunderstanding the behavior of tumors under various experimental conditions. in this work, we havestudied the growth proper...