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Beyond-Mean-Field Effects in Rabi-Coupled Two-Component Bose-Einstein Condensate.
L Lavoine1, A Hammond1, A Recati2
1Laboratoire Charles Fabry, UMR 8501, Institut d'Optique, CNRS, Université Paris-Saclay, Avenue Augustin Fresnel, 91127 Palaiseau CEDEX, France.
Physical Review Letters
|December 3, 2021
Summary
We explore beyond-mean-field effects in Bose-Einstein condensates (BECs). Rabi coupling modifies the energy density, revealing new two- and three-body interactions crucial for stabilizing BEC mixtures.
Area of Science:
- Quantum physics
- Atomic physics
- Condensed matter physics
Background:
- Bose-Einstein condensates (BECs) are quantum states of matter.
- Beyond-mean-field (BMF) effects are crucial for understanding BECs.
- Two-component BECs with tunable interactions are ideal for studying BMF physics.
Purpose of the Study:
- To theoretically calculate and experimentally measure the BMF equation of state in a coherently coupled two-component BEC.
- To investigate the role of Rabi coupling in modifying the BMF energy density.
- To observe the emergence of new two- and three-body interactions.
Main Methods:
- Theoretical calculations of the BMF equation of state.
- Experimental measurements using a coherently coupled two-component BEC of 39K.
- Analyzing the expansion dynamics of the BEC with and without Rabi coupling.
- Investigating the density and Rabi-coupling frequency (Ω) dependence of the energy density.
Main Results:
- The BMF energy density transitions from Lee-Huang-Yang scaling to integer power-law scaling with increasing Ω.
- A novel two-body BMF term (∝n^2√Ω) and a repulsive three-body term (∝n^3/√Ω) were identified.
- Experimental evidence for these contributions was obtained from the expansion dynamics of a Rabi-coupled 39K condensate.
- Rabi coupling was shown to preserve spin composition, preventing drift from the vanishing mean-field point.
Conclusions:
- Rabi coupling plays a critical role in controlling BMF effects in two-component BECs.
- The observed two- and three-body interactions provide new insights into quantum many-body physics.
- Rabi coupling offers a method to stabilize BEC mixtures, enabling the study of phenomena in systems with spin-asymmetric losses.
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