High-resolution error detection in the capture process of a single-electron pump

作者：Giblin S P^*; See P; Petrie A; Janssen T J B M; Farrer I; Griffiths J P; Jones G A C; Ritchie D A; Kataoka M

来源：Applied Physics Letters, 2016, 108(2): 023502.

DOI：10.1063/1.4939250

The dynamic capture of electrons in a semiconductor quantum dot (QD) by raising a potential barrier is a crucial stage in metrological quantized charge pumping. In this work, we use a quantum point contact (QPC) charge sensor to study errors in the electron capture process of a QD formed in a GaAs heterostructure. Using a two-step measurement protocol to compensate for 1/f noise in the QPC current, and repeating the protocol more than 10 6 times, we are able to resolve errors with probabilities of order 10(-6). For the studied sample, one-electron capture is affected by errors in similar to 30 out of every million cycles, while two-electron capture was performed more than 10(6) times with only one error. For errors in one-electron capture, we detect both failure to capture an electron and capture of two electrons. Electron counting measurements are a valuable tool for investigating non-equilibrium charge capture dynamics, and necessary for validating the metrological accuracy of semiconductor electron pumps.

• 出版日期2016-1-11