Robust Noise Modulation of Nonlinearity in Carbon Nanotube Field-Effect Transistors

Carbon nanotubes (CNTs) are one of the candidates for nanosize devices such as field-effect transistors. CNT field-effect transistors (CNTFETs) have very special properties sometimes caused by surface states. For example, they are also well known as noisy devices caused by the molecule adhesion on the surface. Nonlinear systems, however, have some advantages such as weak signal detection or enhancement in working with noise. The small signal enhancement was conventionally studied as stochastic resonance. Therefore, we study the modification of nonlinearity of the systems under noise. For actual applications, the noise is also generated from the devices. Thus, we combined the noise CNTFET and another CNT transistor for the trial nonlinear system. Then, the sine wave amplification in the transistor with 1/f noise of CNTFETs was measured. We used two different combinations of CNTFETs for noise and nonlinear CNTFETs, and observed the robustness of the noise modification on the nonlinearity. (C) 2010 The Japan Society of Applied Physics