Negative transconductance in trench-type InGaAs/InAlAs quantum wire FET

The effects of negative differential resistance (NDR) and negative transconductance are observed in an InGaAs/InAlAs (25/sup w//spl times/10/sup t/ nm) quantum wire (QWR)-field effect transistor (FET) that is fabricated with a trench-type QWR grown on a (311)A V-groove patterned InP substrate by molecular beam epitaxy (MBE). The quantized conductance fluctuations are clearly observed at the relatively high temperature of 24 K, which indicates a high quality QWR is realized by our novel trench type epitaxial growth method. The quantized conductance result can be explained by the energy sub-level related resonant tunneling like phenomenon between one-dimensional states of the QWR and the two-dimensional states of the reservoir. Especially, the negative transconductance characteristics are observed at 6 K.