Abstract
We study the early-time dynamics of a degenerate Bose gas after a sudden quench of the interaction strength, starting from a weakly interacting gas. By making use of a time-dependent generalization of the Nozières-Saint-James variational formalism, we describe the crossover of the early-time dynamics from shallow to deep interaction quenches. We analyze the coherent oscillations that characterize both the density of excited states and the Tan's contact as a function of the final scattering length. For shallow quenches, the oscillatory behavior is negligible and the dynamics is universally governed by the healing length and the mean-field interaction energy. By increasing the final scattering length to intermediate values, we reveal a universal regime where the period of the coherent atom-molecule oscillations is set by the molecule binding energy. For the largest scattering lengths we can numerically simulate in the unitary regime, we find a universal scaling behavior of the typical growth time of the momentum distribution in agreement with recent experimental observations [C. Eigen et al., Nature 563, 221 (2018)10.1038/s41586-018-0674-1].
| Original language | English |
|---|---|
| Article number | 023623 |
| Number of pages | 10 |
| Journal | Physical Review A |
| Volume | 99 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 21 Feb 2019 |
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Early-time dynamics of Bose gases quenched into the strongly interacting regime. / Muñoz de las Heras, A.; Parish, M. M.; Marchetti, F. M.
In: Physical Review A, Vol. 99, No. 2, 023623, 21.02.2019.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Early-time dynamics of Bose gases quenched into the strongly interacting regime
AU - Muñoz de las Heras, A.
AU - Parish, M. M.
AU - Marchetti, F. M.
PY - 2019/2/21
Y1 - 2019/2/21
N2 - We study the early-time dynamics of a degenerate Bose gas after a sudden quench of the interaction strength, starting from a weakly interacting gas. By making use of a time-dependent generalization of the Nozières-Saint-James variational formalism, we describe the crossover of the early-time dynamics from shallow to deep interaction quenches. We analyze the coherent oscillations that characterize both the density of excited states and the Tan's contact as a function of the final scattering length. For shallow quenches, the oscillatory behavior is negligible and the dynamics is universally governed by the healing length and the mean-field interaction energy. By increasing the final scattering length to intermediate values, we reveal a universal regime where the period of the coherent atom-molecule oscillations is set by the molecule binding energy. For the largest scattering lengths we can numerically simulate in the unitary regime, we find a universal scaling behavior of the typical growth time of the momentum distribution in agreement with recent experimental observations [C. Eigen et al., Nature 563, 221 (2018)10.1038/s41586-018-0674-1].
AB - We study the early-time dynamics of a degenerate Bose gas after a sudden quench of the interaction strength, starting from a weakly interacting gas. By making use of a time-dependent generalization of the Nozières-Saint-James variational formalism, we describe the crossover of the early-time dynamics from shallow to deep interaction quenches. We analyze the coherent oscillations that characterize both the density of excited states and the Tan's contact as a function of the final scattering length. For shallow quenches, the oscillatory behavior is negligible and the dynamics is universally governed by the healing length and the mean-field interaction energy. By increasing the final scattering length to intermediate values, we reveal a universal regime where the period of the coherent atom-molecule oscillations is set by the molecule binding energy. For the largest scattering lengths we can numerically simulate in the unitary regime, we find a universal scaling behavior of the typical growth time of the momentum distribution in agreement with recent experimental observations [C. Eigen et al., Nature 563, 221 (2018)10.1038/s41586-018-0674-1].
UR - http://www.scopus.com/inward/record.url?scp=85062294303&partnerID=8YFLogxK
U2 - 10.1103/PhysRevA.99.023623
DO - 10.1103/PhysRevA.99.023623
M3 - Article
VL - 99
JO - Physical Review A
JF - Physical Review A
SN - 2469-9926
IS - 2
M1 - 023623
ER -