PhD students' seminar: Alfred HAMMOND

Seminar for PhD students given by Alfred Hammond, from the Quantum Gases group, on 17 March 2022 at 1:15 pm in the auditorium / or the amphi of the Institut d'Optique in Palaiseau, on the topic: "3-particle interactions in a mixture of two dilute Bose-Einstein condensates."

Abstract: "The experimental study of quantum gases is a field of research that emerged in the late 1990s (Nobel Prize 2001). In such gases, the low particle density and the very low temperature impose a simple form for the interaction energy between atoms: the internal energy of the gas is then proportional to the number of pairs of particles and the proportionality coefficient (denoted g) depends only on the internal state of the atoms. After explaining in more detail the physical origin of this model, I will present several methods to externally control the strength of the interactions (g), especially in a quantum gas mixture. Beyond this model, the latest results of our team, and their experimental proof, show the appearance of a new preponderant term proportional to the cube of the density in the internal energy of a coherent mixture of quantum gases. Finally, the equation of state of the mixture becomes richer, which opens the way to interesting phase transitions such as that of quantum droplets."