Events at Physics
Events on Thursday, September 15th, 2011
- R. G. Herb Condensed Matter Seminar
- How d-wave pair fluctuations arise from strong electronic correlations
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: William Putikka, Ohio State University
- Abstract: Superfluid behavior is relatively common in strongly correlated fermion systems, suggesting there is a common reason for this behavior rooted in the strong correlations. In previous calculations I found d-wave pair fluctuations in the 2D t-J model on a square lattice. Having pair fluctuations in a well-defined strongly correlated model allows for a detailed examination of the model's properties for the model parameters where the pair fluctuations are strongest. From this analysis I propose a robust process for producing pair fluctuations by strong correlations. As part of the analysis I find that d-wave pair fluctuations are not due to antiferromagnetic spin fluctuations, instead the AF fluctuations compete with the pair fluctuations. I will also discuss how these ideas may generalize across a broader range of strongly correlated systems.
- Host: Robert Joynt
- Atomic Physics Seminar
- Reusable Neutral Atom Qubits for Quantum Information Applications
- Time: 2:00 pm
- Place: 5310 Chamberlin
- Speaker: Michael Gibbons, Georgia Institute of Technology
- Abstract: Most neutral atom quantum computing experiments rely on destructive state detection techniques that eject the detected qubits from the trap. These techniques limit the repetition rate of these experiments due to the necessity of reloading a new quantum register for each operation.
We address this problem by developing reusable neutral atom qubits. Individual 87Rb atoms are trapped in an optical lattice and are held for upwards of 300 s. Each atom is prepared in an initial quantum state and the state is subsequently detected with 95% accuracy and with less than a 1% probability of losing it from the trap. The combination of long storage times and lossless state detection could help facilitate the development of faster and more complex quantum operations that will enable future advancements in the field of neutral atom quantum information.
- Host: Saffman
- Astronomy Colloquium
- Reconnection Diffusion: Changing the Star Formation Paradigm
- Time: 3:30 pm - 5:00 am
- Place: 4421 Sterling Hall
- Speaker: Professor Alexander Lazarian
- Abstract: For decades the idea that star formation is regulated by ambipolar diffusion dominated theories of star formation. Recent observational data shows that the traditional textbook paradigm has serious problems. At the same time recent progress in understanding th magnetic reconnection in realistically turbulent environments provides a different scenario of star formation, which is based on a new concept termed reconnection diffusion. I shall discuss the idea of fast reconnection in turbulent media, which is the basis of reconnection diffusion, problems with explaining the existing observational data and the theoretical predictions that the reconnection diffusion entails.
- Host: Astronomy Department
- Graduate Introductory Seminar
- Theoretical Nuclear, Particle, Astrophysics, and Cosmology Seminar
- Time: 5:30 pm
- Place: 2223 Chamberlin Hall
- Speaker: Ramsey-Musolf