Goodbye to Leslie Ross, who returns to the University of Illinois, Urbana-Champaign, to continue her pursuit of a PhD in condensed matter theory. Leslie spent the summer here as part of an NPSC Graduate Fellowship doing important research on the memory error rates of silicon qubits in quantum computers. Good luck to her, a truly […]
The spin of an electron in silicon may act as an information carrier in future information technologies, from quantum computers to spintronics. For quantum information applications, the spin of cold localized electrons in silicon can make a good quantum memory due to the purifiability of the spin environment (a spin-0 nuclear isotope is available) and […]
Welcome to the new website for the Tahan research group. Please bear with us as past and current information is slowly added.
Phys. Rev. A, 77, 5, 053819 (2008)
Systems of coupled photonic cavities have been predicted to exhibit quantum phase transitions by analogy with the Hubbard model. To this end, we have studied topologies of few (up to six) photonic cavities each containing a single two-level system. Quantum phase space diagrams are produced for these systems, and compared to mean-field results. We also consider finite effective temperature, and compare this to the notion of disorder. We find the extent of the Mott lobes shrink analogously to the conventional Bose-Hubbard model.
Speaker: Charles Tahan. About the talk: As a physicist, I will give a somewhat un-physics perspective on quantum information science and technology, both via some of my own scientific work, but mostly from the vantage of science and technology studies. My own pet name for the field, spookytechnology, provides a good starting point for the discussion. We will touch on why the new quantum revolution is for real (including some cool examples), what “new quantum revolution” actually means, why it’s more interesting than nanotechnology, and how we should prepare for it, both personally and societally.
Phys. Rev. Lett. 100, 216401 (2008)
The superfluid to Mott insulator transition in cavity polariton arrays is analyzed using the variational cluster approach, taking into account quantum fluctuations exactly on finite length scales. Phase diagrams in one and two dimensions exhibit important non-mean-field features. Single-particle excitation spectra in the Mott phase are dominated by particle and hole bands separated by a Mott gap. In contrast to Bose-Hubbard models, detuning allows for changing the nature of the bosonic particles from quasi-localized excitons to polaritons to weakly interacting photons. The Mott state with density one exists up to temperatures $T/g\gtrsim0.03$, implying experimentally accessible temperatures for realistic cavity couplings $g$.
Exploring advanced classical and quantum technologies and their societal implications. Definitions and essays on nanotechnology and quantum technology.
A new era of physics careers in industry is about to begin, based on the quantum information science/technology (QIS/T) revolution. Whether this statement is true, or can be made to be true, is something we should consider. From my viewpoint, the chances are improving, but there are still roadblocks.
Read more…
As physics and engineering extend their reach to the control of single excitations of nature, we gain the ability to explore and even design the interaction of matter and energy in fundamentally new ways. One of the most interesting opportunities this presents is controllable interactions between many quantum particles — such as electrons — which is traditionally the realm of condensed matter physics. The questions we asked ourselves were these: Can we also do this with light? Can it be useful? We show that the answer is YES!
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 […]
