Special Colloquium
Department of Physics, NCU
The unexplored world of composite quantum particles: two effects taken from cold-atom physics
Speaker
Dr. Shiue-Yuan Shiau (蕭學遠)
Research Center for Applied Sciences,Academia Sinica
Date 2018.02.05 (Mon)
Time 14:00
Place S4-625
Abstract:
I will first explain the fundamental difficulty raised by the many-body effects between composite quantum particles, which comes from the Pauli exclusion principle between the particle fermionic components, and which makes standard Green functions and Feynman diagrams quite inappropriate.
Then, I will present the Shiva diagrams proposed by Monique Combescot, which render these many-body effects easy to visualize and thus to predict.
Among the works I have done using this formalism – still mastered by very few people today – I will focus on two recent ones:
1) the scattering between cold-atom dimers, in which the fermion exchanges induced by the Pauli exclusion principle significantly decrease the scattering length.
2) the prediction of high interference patterns in the collision of two cold-atom condensates, as a nontrivial signature of the particle composite nature.