Search Talks

I will present recent work [1] on preparation by measurement of Greenberger–Horne–Zeilinger (GHZ) states in circuit quantum electrodynamics. In particular, for the 3-qubit case, when employing a nonlinear filter on the recorded homodyne signal the selected states are found to exhibit values of the Bell–Mermin operator exceeding 2 under realistic conditions. I will discuss the potential of the dispersive readout to demonstrate a violation of the Mermin bound, and present a measurement scheme avoiding the necessity for full detector tomography. [1] Lev S Bishop et al 2009 New J. Phys. 11 073040

In addition to its ability to probe Inflation, CMB polarization offers the intriguing possibility to detect CP-symmetry violation. In some sense these predictions, if true, would be more surprising than confirmation of the inflationary paradigm -- for which ample, albeit circumstantial, evidence already exists. Moreover, recent theoretical predictions imply that, not only are parity violating CMB polarization effects possible, but that they have already been detected at 3\sigma confidence levels in existing polarization data. I will present a worked example showing the impact of experimental systematic effects on such measurements, and present a robust test to help determine the veracity of the theoretical predictions. I will show that the CP-symmetry violating observables are more susceptible to certain systematic effects, and discuss the future prospects for such CMB polarization probes of fundamental physics.

I will tell how the story given in Umberto Eco's book The Search for the Perfect Language continues with modern work on logical and programming languages.(For more information, see http://www.umcs.maine.edu/~chaitin/hu.html.)