A simple version of Schrödinger’s cat — an electron that simultaneoulsy exists in two distinct electronic states — has been created in a phosphorus-doped silicon semiconductor by P. T. Greenland and team, University College London, UK.
Working with colleagues in the Netherlands, Greenland used a short, high-intensity pulse from a far-IR laser to create the state of quantum superposition. The coherent mixtures of the different orbital states were shown to have dephasing times three orders of magnitude larger than the frequency of transitions between orbitals.
They also demonstrated that the superposition state could be controlled so that the electrons emit a photon echo at a well-defined time after the superposition was created.
Co-author Paul Murdin notes, “Our work shows that some of the quantum engineering already demonstrated by atomic physicists using cold atom traps, can be implemented in the type of silicon chip used in making the much more common transistor.”