Find out the latest developments in our bottom-up superconducting silicon work.
Charles Tahan selected to receive the Presidential Early Career Award for Scientists and Engineers (PECASE)
President Obama today named 102 researchers as recipients of the Presidential Early Career Awards for Scientists and Engineers, the highest honor bestowed by the United States Government on science and engineering professionals in the early stages of their independent research careers.
Preprint: Relaxation of excited spin, orbital, and valley qubit states in single electron silicon quantum dots
We review and expand on previous work that treats relaxation physics of low-lying excited states in ideal, single electron, silicon quantum dots in the context of quantum computing. These states are of three types: orbital, valley, and spin. The relaxation times depend sensitively on system parameters such as the dot size and the external magnetic […]
The science of how light interacts with matter is called quantum electrodynamics or QED and the theory on which it is based is one of the crowning achievements of 20th century physics.
Today, it lies at the heart of an emerging technology called circuit-QED, in which photons trapped on a silicon chip are made to interact with superconducting devices called artificial atoms, which have various energy levels just like real atoms.
This is a promising tool for quantum computation. Circuit-QED devices manipulate quantum information as it is transferred from light to matter and vice versa. And the fact that this all takes place on a single chip allows unprecedented control.
But there is another way of doing this kind of quantum information processing that could be just as promising. Instead of relying on light, this uses quantum packets of sound called phonons.
Condensed-matter physicists have their own particle zoo – a menagerie filled with familiar and exotic quasiparticles including old favourites like holes and phonons, and newer additions such as surface plasma polaritons. Quasiparticles are excitations in a solid that behave like tiny particles and obey quantum mechanics. A phonon for example, is a quantized sound wave that propagates through a crystal.
Now Charles Tahan and colleagues at the Laboratory for Physical Sciences just outside Washington, DC have shown that the interaction between phonons and electronic excitations in certain semiconductors can be described in terms of a brand new quasiparticle called the phoniton.
Theorists propose an experiment to observe a “phoniton,” a novel hybrid of an electron and a quantum of vibration in a crystal lattice.
Vibrations in a crystal can combine with an electron in a new way to form a hybrid quantum entity, according to a team of theorists publishing in Physical Review Letters. They call it a “phoniton,” a particle that combines a phonon—the quantum form of vibrations—with a matter excitation, such as an electron that transits between two levels. The team also proposes a nanostructure that would support this quantum state and allow it to be observed.
“Phononiton” has become “phoniton” by negotiation with the editors of PRL. It’s etymologically cleaner. The good news is that our paper has been accepted for publication in PRL and the new term “phoniton” has been accepted as well. See our summary for more information.
In 2005 we predicted “quantum phase transitions of light.” It seemed crazy at the time. Check out number 6: Physics World reveals its top 10 breakthroughs for 2010.
Spookytechnology and Society: Understanding and anticipating the second revolution in quantum-designed technologies Download the article this summary is based on: C. Tahan, Spookytechnology and Society, submitted for publication. The original preprint can be found on the arxiv (Oct 12, 2007): arXiv:0710.2537. • tahan.com/charlie: Technology and Society • Wikipedia: quantum physics, quantum entanglement, quantum computer Some early press on the preprint […]