Event calendar file
Department of Nuclear and Atomic Physics Seminars
Observing Quantum Trajectories
by Dr. G. Rajalakshmi (DHEP, TIFR)
Thursday, September 8, 2011
from
to
(Asia/Kolkata)
at Colaba Campus ( P305 )
at Colaba Campus ( P305 )
| Description |
Uncertainty principle forbids discussion of quantum paths or trajectories as position and momentum of a quantum particle cannot be simultaneously specified precisely. But by using the concept of "weak measurements"[1,2], one can determine the "average" trajectory of an ensemble of quantum particles. Though this appears to contradict conventional interpretation of quantum mechanics, it can be explained by standard measurement theory. In the scheme proposed by Abaronov et. al [1], and clarified further by Sudarshan et al, one 'weakly' measures the value of one property of a quantum system, without disturbing its further evolution. A strong measurement of a conjugate property of the system then post-selects from the measured events. Repeating such measurements over an ensemble helps deduce an average value for the 'weakly' measured property. Kocsis et. al [2] performed such a "weak measurement " of the average trajectories of single photons in a two-slit interferometer. In this talk, I will discuss the principle of "weak measurements" and describe the experiment of Kocsis et. al. References: [1] Aharonov Y, Albert D, Vaidman L, Phys. Rev. Lett., 60, 1988, 1352. [2] Duck I M, Stevenson P M, Sudarsham E C G, Phy. Rev. D, 40, 1989, 2112. [3] Kocis S, et. al, Science. 332, 2011, 1170. |
| Organised by | Dr. Vaibhav Prabhudesai |
