Types of dispersion

phase dispersion

the high phase dispersion is always advantageous as it greatly alter the group index of the medium

 dispersion

back action concept

Back action refers (in the regime of quantum systems) to the effect of a detector on the measurement itself, as if the detector is not just making the measurement but also affecting the measured or observed system under a perturbing effect. Back action has important consequences on the measurement process, and is a significant factor in measurements near the quantum limit, such as measurements approaching the Standard Quantum Limit (SQL).

https://en.wikipedia.org/

atom-atom interaction in BEC

Two magnets interact with each other through a force that depends on the distance between them and on their

mutual orientation. How do these long-range dipolar forces affect the behavior of a system of many magnets?

Science 352 (6282), 201-205

EIT

It is well-known that EIT is a quantum interference effect occurring in three-level atoms. When
the auxiliary strong control field exists, the resonance absorption peak of the three-level atomic
ensemble is completely suppressed and a transparent window appears.

Vol. 28, No. 4 / 17 February 2020 / Optics Express

Poor adsorption on strong dispersion in EIT

EIT allows one to render the material highly transparent and still retain the strong dispersion required for the generation of
slow light. 

Methods for controlling the group velocity of light

There are two standard methods for controlling the group velocity of light. One makes use of the dispersive properties associated with the

resonance structure of a material medium. The other makes use of structural resonances, such as those that occur in photonic crystals

J. Opt. Soc. Am. B / Vol. 28, No. 12 / December 2011

BEC

 Atoms in Bose–Einstein condensate 
interact coherently

presence of collisions on quantum interference

the electromagnetically induced transparency process involves delicate quantum interference between two quantum amplitudes, and the presence of collisions or other dephasing phenomena can destroy this interference. 

https://www.photonics.com/Articles/Slow_Light_From_Basics_to_Future_Prospects/a24576

اهمیت علم و آموزش

برای رشد و تعالی جامعه می‌توان برنامه‌های کوتاه مدت داشته باشید مثلا گندم بکارید و سال بعد برداشت کنید. برای برنامه‌های میان مدت درخت بکارید مثلا صنعت و کشاورزی و کارخانه ولی برای برنامه‌های بلند مدت باید آموزش داد

Second quantization

Second quantization, also referred to as occupation number representation

brain drain

"brain drain"