Liquid-induced damping of mechanical feedback effects in single electron tunneling through a suspended carbon nanotube

摘要

In single electron tunneling through clean, suspended carbon nanotube devicesat low temperature, distinct switching phenomena have regularly been observed.These can be explained via strong interaction of single electron tunneling andvibrational motion of the nanotube. We present measurements on a highly stablenanotube device, subsequently recorded in the vacuum chamber of a dilutionrefrigerator and immersed in the 3He/4He mixture of a second dilutionrefrigerator. The switching phenomena are absent when the sample is kept in theviscous liquid, additionally supporting the interpretation of dc-drivenvibration. Transport measurements in liquid helium can thus be used for finitebias spectroscopy where otherwise the mechanical effects would dominate thecurrent.