New Insights into Nanoscale Electronics
 

Physicists from Hannover and Geneva investigate single electron transport through semiconductor nanostructure

The basic building block in conventional electronics is the transistor; a computer, for example, contains more than a billion transistors and worldwide nearly 10 billion transistors are produced each second. Now, researchers of QUEST (Centre for Quantum Engineering and Space-Time Research) at Leibniz Universität Hannover, Germany, and University of Geneva, Switzerland, have gained new insights into the quantum mechanical behavior of a nanoscale single-electron transistor, a so-called quantum dot.

Quantum dots are tiny nano-structures that can be manufactured using modern nanofabrication technologies. Quantum dots typically contain only a few electrons and they mimic in many ways the behavior of an atom. A minute electrical can run through a quantum dot due a quantum mechanical phenomenon known as tunneling, which allows single electrons at a time to enter and leave the quantum dot. A quantum dot can therefore act as a transistor for single electrons.

In the experiment the researchers measured the electrical current running through a quantum dot. The researchers recorded the individual electrons passing through the transistor and could thus accurately determine the sequence of single electrons transferred one after another through the quantum dot. In particular, they were able to measure the tiny fluctuations of the electrical current in the single-electron transistor and the correlations between different electronic tunneling processes.

The researchers from Hannover and Geneva were able to measure the transfer of single electrons with unprecedented precision and they thereby gained valuable information about the fundamental quantum mechanical phenomenon of tunneling. These findings are not only important for the basic sciences; they are also expected to lead to practical applications, for example in quantum encryption of data and in the realization of a quantum computer using single-electron transistors.

The article “Measurement of finite-frequency current statistics in a single-electron transistor” is published online in the January issue of Nature Communications (DOI: 10.1038/ncomms1620).

Contact
Prof. Dr. Rolf J. Haug
Institute of Solid State Physics, Dept. Nanostructures
Tel. +49 511.762 2901
E-mail: haug@nano.uni-hannover.de

Dr. Ude Cieluch
QUEST Communication
Tel.: +49 511.762 17481
E-mail: ude.cieluch@nano.uni-hannover.de

Meldung vom 25.01.2012