Confined bulk states as a long-range sensor for impurities and a transfer channel for quantum information

Abstract

We show that confinement of bulk electrons can be observed at low-dimensional surface structures and can serve as a long-range sensor for the magnetism and electronic properties of single impurities or as a quantum information transfer channel with large coherence lengths. Our ab initio calculations reveal oscillations of electron density in magnetic chains on metallic surfaces and help to unambiguously identify the electrons involved as bulk electrons. We furthermore discuss the possibility of utilizing bulk state confinement to transfer quantum information, encoded in an atom's species or spin, across distances of several nanometers with high efficiency.