Hybrid single-electron transistor as a source of quantized electric current

The basis of synchronous manipulation of individual electrons in solid-state devices was laid by the rise of single electronics about two decades ago. Ultrasmall structures in a low-temperature environment form an ideal domain for addressing electrons one by one. In the so-called metrological triangle, voltage from the Josephson effect and resistance from the quantum Hall effect would be tested against current via Ohms law for a consistency check of the fundamental constants of nature, \[planck] and e (ref.4). Several attempts to create a metrological current source that would comply with the demanding criteria of extreme accuracy, high yield and implementation with not too many control parameters have been reported. Here, we propose and prove the unexpected concept of a hybrid normal-metal-superconductor turnstile in the form of a one-island single-electron transistor with one gate, which demonstrates robust current plateaux at multiple levels of ef at frequency f.