Bose-Einstein Condensation of Molecules

Abstract

We report on the Bose-Einstein condensation of more than 10(5) Li2 molecules in an optical trap starting from a spin mixture of fermionic lithium atoms. During forced evaporative cooling, the molecules are formed by three-body recombination near a Feshbach resonance and finally condense in a long-lived thermal equilibrium state. We measured the characteristic frequency of a collective excitation mode and demonstrated the magnetic field-dependent mean field by controlled condensate spilling.

Ultra-cold ion–atom collisions: near resonant charge exchange

“…These include applications in condensed-matter physics [4], in the measurement of fundamental constants [5], in quantum computing [6,7] and in ultracold chemistry [8,9]. One open question lies in the role of electrical charges in ultracold systems [10,11].…”

Spectrum and Dynamics of the BCS-BEC Crossover from a Few-Body Perspective

“…By solving the problem from a few-body perspective, we are able to give accurate properties -especially energy levels as well as time-dependent dynamics -of the full quantum mechanical spectrum at zero temperature. As a result we achieve a deeper understanding of the global topology of the spectrum, in addition to making quantitative predictions of transition probabilities and dynamical properties of this system when interactions change with time as in experiments [4,5,6,7,8,9].To obtain the energy spectrum, we use a correlated gaussian basis set [10,11]. A diabatization procedure reduces the system to a tractable number of relevant eigenfunctions, after which we solve the time-dependent Schrödinger equation using the diabatic representation.…”

“…In a recent experiment with optical lattices, the spectrum of two fermions in a trap has been measured [2], demonstrating that few body trapped systems can be studied in their own right. Also, the BCS-BEC crossover has been routinely explored in experiments with ultracold Fermi gases [4,5,6,7,8,9]. In this Letter, we explore the spectrum and dynamics of four trapped particles and we show how a few-body formulation allows us to obtain accurate solutions of the system without making the standard approximations of many-body theory.…”

Бозе-Конденсат Ультрахолодных Атомов В Ловушках: Бозе - Бозе- И Бозе - Ферми-Смеси

“…Из-за принципа Паули ферми-система сама по себе не может быть охлаждена, в отличие от бозе-системы. Однако, находясь в тепло-вом равновесии с взаимодействующим с ней бозе-газом, она охладится в области пересечения бозе-и ферми-систем [25]- [27].…”