Quantum electronics based on electron orbit

University of New South Wales (UNSW) scientists have observed a new kind of interaction between electrons in a single-atom silicon transistor, potentially opening the way to a new kind of electronics. According to the paper published in Physical Review Letters (online 26 January), quantum electronics could be driven by the orbital nature of electrons, in addition to the spin or the charge.

The scientists tuned the symmetry of a complex phenomenon called the Kondo effect in a transistor by applying a strong magnetic field. The findings offer a more complete understanding of the mechanisms for electron transport in nanostructures at the atomic level.

The study, in collaboration with scientists from the ICMM in Madrid and the Kavli Institute in The Netherlands, describes how a single electron bound to a dopant atom in a silicon matrix can interact with many electrons throughout the transistor.

In these geometries, electron-electron interactions can be dominated by something called the Kondo effect. Conventionally, this arises from the spin degree of freedom, which represents an angular momentum intrinsic to each electron and is always in the up or in the down state.

However, researchers also observed that similar interactions could arise through the orbital degree of freedom of the electron. This describes the wave-like function of an electron and can be used to help determine an electrons’ probable location around the atom’s nucleus.

By applying a strong magnetic field, the researchers were able to tune this effect to eliminate the spin-spin interactions while preserving the orbital-orbital interactions.


This story was originally posted by Electronics News.


University of New South Wales