Highly sensitive and broadband carbon nanotube radio-frequency single-electron transistor

We have investigated radio-frequency single-electron transistor operation of single-walled carbon nanotube quantum dots in the strong tunneling regime. At a temperature of 4.2 K and with a carrier frequency of 754.2 MHz, we reach a charge sensitivity of 2.3×10−6e/Hz over a bandwidth of 85 MHz. Our results indicate a gain-bandwidth product of 3.7×1013 Hz(3/2)/e, which is by one order of magnitude better than those for typical radio-frequency single-electron transistors.