Extending the high-frequency limit of a single-electron transistor by on-chip impedance transformation

Single-electron current sources: Toward a refined definition of the ampere

“…th . Equation (35) has an important limit for the maximum coupling with R 1 ¼ R 2 and for small temperature differences jT 1 À T 2 j, namely, G th ¼P =ðT 1 ÀT 2 Þ¼k 2 B T=6ℏG Q , the so-called quantum of thermal conductance (Pendry, 1983). Equation (35) can also be applied in the case where one of the resistors is replaced by an NIN tunnel junction with the corresponding resistance.…”

“…In practice, the capacitance of the biasing leads and the input capacitance of the preamplifier dominate. When the preamplifier is located at room temperature as in the pioneering experiments (Fulton and Dolan, 1987;Kuzmin et al, 1989), the wiring necessarily contributes a capacitance of the order of 0.1-1 nF and henceforth limits the readout bandwidth to the kilohertz range (Pettersson et al, 1996;Visscher et al, 1996). Readout by a current amplifier from a voltage-biased SET avoids the RC cutoff on the gain, but the usable bandwidth is not substantially altered as current noise increases at high frequencies where the cabling capacitance shorts the current amplifier input (Starmark et al, 1999).…”

“…Bandwidths up to 700 kHz have been achieved by utilizing a high-electronmobility transistor (HEMT) amplifier with a low impedance output at the sample stage (Pettersson et al, 1996;Visscher et al, 1996). The dissipated power at the HEMT in these studies was 1-10 W depending on the biasing, which can easily result in overheating of the electrometer and/or the coupled single-electron device.…”

“…Extensive theoretical work, e.g., on topological Chern numbers, has strengthened the confidence in the exactness of R K ; see Avron, Osadchy, and Seiler (2003), Bieri and Fröhlich (2011), and Doucot (2011) for introductory reviews. Recent theoretical work based on quantum electrodynamics (QED) predicts that the vacuum polarization can lead to a magnetic field dependence of both R K (Penin, 2009(Penin, , 2010a and K J (Penin, 2010b), but only at the level of 10 À20 . The case of single-electron transport has been studied much less and there are no such strong theoretical arguments for the lack of any corrections for the transported charge (Gallop, 2005;Stock and Witt, 2006;Keller, 2008).…”

Noise performance of the radio-frequency single-electron transistor

“…The bandwidth has been increased to 1 MHz by using a low-temperature amplifier close to the SET. 14,15 Such an approach has, however, serious problems due to the power dissipation of the amplifier that increases the sample temperature.…”