Parametric instability in a double-carbon-nanotube nanoelectromechanical detector of modulated terahertz radiation based on two parallel carbon nanotubes

In this paper, we investigate the conditions for excitation of parametric instability in a resonant detector of modulated terahertz radiation based on a system of two coupled (plasma and mechanical) resonators that are a quarter-wave two-wire line section of two identical elastic nanotubes with metallic conductivity. Continuous plasma and mechanical resonators reduce to lumped coupled oscillators. The threshold value of the variable potential amplitude applied to the system under which the parametric instability arises is calculated.