Quantum Lunch Location:
T-Division Conference Room, TA-3,
Building 123, Room 121
Quantum Institute: Visitor Schedule
The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.
For more information, contact Diego Dalvit.
December 8, 2005
Ricardo S. Decca,
Department of Physics, Indiana University-Purdue University Indianapolis
Precision Measurements in the Casimir Regime
In this talk our measurements of forces in the Casimir regime will be presented. The first topics that will be discussed are how to get precise measurements at ~ 100 nm, and why they are important. Our measurements are precise enough to make possible a distinction among different predictions about the thermal dependence of the Casimir interaction. These dependences arise from the use of different models for the interaction between virtual photons and real metals. I will show that our agreement with the theory is better than 0.5% (when the effect of uncertainties are taken into account in both the experiment and the theory) over a wide separation range. I will show some of the approaches taken to minimize the systematics in our set-up.
The second part of the talk deals with the search for hypothetical forces at small separation between the test bodies. Since the Casimir force (of strength ~10 pN for our configuration) is too large a background, it is better to perform a completely different experiment where the effect of the Casimir interaction is minimized (which we call a "Casimir-less" experiment). I will introduce our experimental setup, which yields ~ 6 fN/Hz1/2 sensitivity. The current status in the search for hypothetical forces, and how much we expect to constrain parameter space with our approach will be presented.
Work was done in collaboration with D. López, H. B. Chan, E. Fischbach, D. E. Krause, G. Klimchitskaya and V. M. Mostepanenko.