Mueller Research Group

Department of Physics

Laboratory of Atomic and Solid State Physics

Cornell UniversityIthaca, NY • 14853 • (607)255-1568

Ultracold Atom Theory


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News from our Group

  • The Fate of Quantum Solitons in Ultracold Gases

    Physical systems often exhibit rich spatial structures — be they domains in a magnet, or the distribution of matter in the universe. Dutta and Mueller from Cornell University conducted a theoretical study of ripples which form in a gas cooled near absolute zero, where the rules of quantum mechanics dominate. Previous theory and experiments have shown that these matter-wave “solitons” or “solitary waves” are very long lived, and hence play an important role in the dynamics of cold fluids. Dutta and Mueller explored the interactions within a large array of solitons. They found a variety of unexpected collective motions, including an instability where pairs of solitons collide and annihilate. They found that the instability could be prevented by magnetizing the gas — forming an exotic quantum state first discussed in the 1960’s in the context of superconductors with magnetic impurities. Finding physical systems which display this Fulde-Ferrell-Larkin-Ovchinnikov phase has been difficult, and their work provides an explicit recipe for generating it. Their work will also be important for developing a broader understanding of quantum non-equilibrium dynamics, and guide the next generation of quantum gas experiments. arxiv:1612.04845


[ Ultracold GasesVortices and Topological DefectsBEC-BCS CrossoverRF SpectroscopyPublicationsPresentations ]
simulation of interference between atomic clouds

Ultracold Gases

At room temperatures the behavior of a gas of atoms is dominated by their random thermal motion. Averaged over time this gives simple descriptions in terms of thermodynamic variables such as Temperature and Pressure. As the temperature is lowered, this thermal motion is reduced. The Heisenberg uncertainty principle prevents the atoms from coming to a stop. Instead, at nanokelvin temperatures, quantum mechanics dictates the properties of these atomic gases. We study this strange and beautiful form of quantum matter. (more)