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Observation of Scale Invariance in Two-Dimensional Matter-Wave Townes Solitons
Cheng-An Chen1, Chen-Lung Hung1,2
1Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA.
Physical Review Letters
|July 23, 2021
Summary
Researchers generated two-dimensional (2D) matter-wave Townes solitons and tested scale invariance in Bose gases. They observed consistent scaling laws, even with magnetic dipole-dipole interactions, confirming universal soliton behavior.
Area of Science:
- Quantum physics
- Atomic physics
- Condensed matter physics
Background:
- Two-dimensional (2D) Bose gases are crucial for studying quantum phenomena.
- Townes solitons are fundamental solutions in nonlinear wave physics.
- Scale invariance is a key property in critical phenomena and universal behavior.
Purpose of the Study:
- To achieve near-deterministic generation of 2D matter-wave Townes solitons.
- To perform a precision test of scale invariance in attractive 2D Bose gases.
- To investigate the influence of magnetic dipole-dipole interactions (MDDI) on 2D scale invariance.
Main Methods:
- Inducing shape-controlled modulational instability in elongated 2D matter waves.
- Creating arrays of isolated solitary waves with controlled sizes and peak densities.
- Rescaling solitary-wave density profiles to confirm collapse onto a single, dimensionless curve.
Main Results:
- Successfully generated 2D matter-wave Townes solitons with high fidelity.
- Confirmed scale invariance by demonstrating the collapse of density profiles onto a universal curve.
- Observed that profiles at different coupling constants collapse onto the universal Townes soliton profile.
- Validated the scaling behavior across a 60-fold difference in soliton interaction energies.
- Showed that MDDI in alkali cesium samples conforms to the same scaling law as contact interactions within experimental uncertainty.
Conclusions:
- The study demonstrates a robust method for generating 2D Townes solitons.
- Scale invariance in 2D Bose gases is confirmed, highlighting universal soliton properties.
- Magnetic dipole-dipole interactions do not disrupt the observed 2D scale invariance, validating theoretical predictions.
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