SAMOP 2023 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 68: Quantum Gases: Bosons V
Q 68.4: Vortrag
Freitag, 10. März 2023, 15:15–15:30, B305
How creating one additional well can generate Bose–Einstein condensation — •Mihály Máté1,5, Örs Legeza1, Rolf Schilling2, Mason Yousif3, and Christian Schilling3,4 — 1Wigner Research Centre for Physics, Budapest, Hungary — 2Institut für Physik, Johannes Gutenberg-Universität, Mainz, Germany — 3Clarendon Laboratory, University of Oxford, Oxford, United Kingdom — 4Department of Physics, Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universität, München, Germany — 5Department of Mathematics, Technical University of Munich, Germany
We propose and study a model for N hard-core bosons which allows for the interpolation between one- and high-dimensional behavior by variation of just a single external control parameter s/t. It consists of a ring-lattice of d sites with a hopping rate t and an extra site at its center. Increasing the hopping rate s between the central site and the ring sites induces a transition from the regime with a quasi-condensed number N0 of bosons proportional to √N to complete condensation with N0 ≃ N. In the limit s/t → 0, d → ∞ the low-lying excitations follow from an effective ring-Hamiltonian. An excitation gap makes the condensate robust against thermal fluctuations at low temperatures. These findings are supported and extended by large scale density matrix renormalization group computations. We show that ultracold bosonic atoms in a Mexican-hat-like potential represent an experimental realization allowing one to observe the transition from quasi to complete condensation by creating a well at the hat’s center.