Research Interests

Also see for research highlights.

  • qc / Quantum computing takes advantage of the true operating system of the universe — quantum physics — to build a new foundation for information science and technology.

  • spins / A quantum bit or “qubit” can be implemented in many possible physical systems. One great option are spin-1/2 particles like electrons, which physicists often think of as tiny magnets, so you can label the spin pointing “up” as |0> and pointing “down” as |1>. The physics of spins in semiconductors is also of interest to other fields like spintronics and sensing.

  • quantum-silicon / Silicon, in an amazing coincidence, is a terrific material for quantum computing. In particular, isotopically enriched silicon (where the silicon-29 are removed) enable incredibly long qubit memory times for a solid-state system.

  • super / An alternative and also promising solid-state qubit technology is based on superconducting circuits where artificial atoms can be constructed out of non-linear harmonic oscillator circuits. The physics of superconductivity/superfluidity in various systems from real superconductors to atomic/photonic emulators continues to be a growing and important area of research.

  • super-semi / Can you combine the best properties of superconductors and semiconductors in one system for quantum and other technologies? There’s been recent progress in so-called superconducting-semiconductor systems that leads us to be believe that this may be possible.

  • quantum-phonons / Phonons are the quantized collective excitations of sound or heat in a material. There are whole new fields sprouting in “nanomechanics” and “optomechanics” that take advantage of nanoscale mechanical systems, using them for example as an intermediary to interconvert photons between frequencies and much more. In particular we have looked at phonon systems in silicon and other crystals and predicted how quantum cavity phonodynamics, an analog of cavity-QED, should be realizable.

  • many-body light (sound) / Superconductivity and other quantum many body phenomena emerges from the strong interactions between electrons, for example. Photons don’t typically interact with each other however. We showed and are interested in how “strongly correlated photon” systems (or “solid-light” in the early days) can be achieved. We’ve also looked at many-body quantum phononic systems.

  • new-nano / Device physics that doesn’t quite fit in the other categories.

  • tech-society / From “nanotechnology” to quantum technology, the impact of science on society (and vice-versa) is worth thinking about. Science outreach also goes here.


Charles Tahan
Physicist in Washington, D.C.