Zero-bias anomaly in resonant tunneling: the role of contact asymmetry

We study the zero-bias anomaly in resonant tunneling through a carbon nanotube quantum dot caused by dissipative environment. At the base temperature, we find a qualitative difference between the cases of symmetric and asymmetric barriers defining the quantum dot. The observed behavior is compared to the theoretical predictions for a physically similar picture of resonant tunneling in Luttinger liquid.