23/05/2013, 15:00 — 16:00 — Sala P3.10, Pavilhão de Matemática
Klaas Bergmann, Technical University Kaiserslautern
Population transfer between quantum states to perfection:
Stimulated Raman Adiabatic Passage (STIRAP)
In many areas of science (e.g. physics, chemistry, quantum
information) controlled modification and in particular efficient
transfer of population between quantum states is wanted. Many
schemes are known that allow varying the usually thermal population
distribution. Of particular interest are means for selective and
efficient transfer of population from quantum state \(i\) to
quantum state \(f\). “Efficient” means that nearly 100% of the
population residing initially in state \(i\) reaches state \(f\).
This also implies high selectivity as no other quantum state
receives population. Traditional techniques such as Raman
scattering, optical pumping or stimulated emission pumping fail to
reach the goal. Spontaneous emission, which channels population
into other levels,is a main problem. STIRAP solves that problem
through a surprisingly simple, but at first glance very puzzling,
sequence of radiative interactions: The quantum system is first
exposed to the radiation field which connects the final state with
an intermediate state (thus, it does not couple to the quantum
state which carries initially the population) before the second
radiation field couples the initial state to the same intermediate
one. The basic phenomena and the physics building blocks of this
process, the concept of which is now applied in very many areas,
are presented and explained.
Apoiado por: Phys-Info (IT), SQIG (IT), CeFEMA e CAMGSD, com financiamento de FCT, FEDER and EU FP7, especificamente via o Doctoral Programme in the Physics and Mathematics of Information (DP-PMI), os projectos estratégicos FCT PEst-OE/EEI/LA0008/2013 e UID/EEA/50008/2013, o projecto IT QuSim, o projecto CRUP-CPU CQVibes, a Acção de Coordenação FP7 QUTE-EUROPE (600788) e os projectos FP7 Landauer (GA 318287) e PAPETS (323901).