We review recent precision measurements on semiconductor tunable-barrier electron
pumps operating in a ratchet mode. Seven studies on five different designs of pumps have …

We present the latest improvements in the traceable measurement and generation of small
electric currents. A central tool in our traceability chain for small direct currents is a new …

The ultrastable low-noise current amplifier (ULCA) was developed as an advanced
instrument for the improved measurement of currents generated by single-electron transport …

This paper describes two systems recently developed at the National Physical Laboratory
(NPL), Teddington, UK, for the generation and measurement of dc currents in the range 100 …

Generating ultra-low currents using resistors is impractical especially in integrated circuits
due to the wasting of much area associated with the required very large resistors. In this …

We measure the frequency dependence of a sample of commercial air-and gas-dielectric
capacitors between 1 kHz and≈ 0.01 Hz. We find that the capacitance of sealed-gas …

This paper provides a comprehensive overview of the historical background, current status,
and future prospects related to the generation and measurement of small electric currents. It …

A current source, which is to be employed in the calibration of low-current meters
(picoammeters and electrometers), is presented here. The output current range is 100 fA to …

We report on the development of a novel highly linear voltage ramp generator to be used for
the traceable calibration of picoamperemeters. The generator is based on two digital-to …

An ultrastable low-noise current amplifier (ULCA) has been transferred between two
laboratories, National Physical Laboratory (NPL) and Physikalisch-Technische …