Broadening of the transition between charge states in the single-electron box by the measurement process

TL;DR

This study investigates how the measurement process influences charge state transitions in a single-electron box, revealing that coupling to a measurement device broadens transition widths beyond isolated predictions.

Contribution

It demonstrates experimentally and theoretically that measurement coupling causes broadening of charge transitions in a single-electron box, extending existing models.

Findings

Transition broadening observed experimentally

Coupling effects quantified within sequential tunneling model

Measurement process impacts charge state stability

Abstract

We report on measurements on a sample consisting of two nominally identical single-electron transistors the islands of which are coupled capacitively. One transistor at a time is operated as electron box. The remaining transistor is used as an electrometer to measure the charge on the box island. While ramping up the box gate voltage transitions occur periodically between states which differ in the charge on the box island by the elementary charge. This shows up in jumps of the electrometer current. The coupling between the box and the measuring device causes a broadening of the transition width not included in the formulae for an isolated box. This is evident in our data as well as from a thorough analysis of the system in the framework of the sequential tunneling model.