Self-consistent determination of the many-body state of ultracold bosonic atoms in a one-dimensional harmonic trap

Marchukov, Oleksandr V.; Fischer, Uwe R.

doi:10.1016/j.aop.2019.03.023

Cited by 10 publications

(8 citation statements)

References 60 publications

(87 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The beyond-mean-field corrections captured by our method (cf. [69,70]) are crucial for this effect. [59,71,72] (see also Appendix C), which disagree with the ML-MCTDHB results and suggest m eff /m > 1.…”

Section: A Case With C < Gmentioning

confidence: 98%

Effective approach to impurity dynamics in one-dimensional trapped Bose gases

et al. 2019

View full text Add to dashboard Cite

We investigate a temporal evolution of an impurity atom in a one-dimensional trapped Bose gas following a sudden change of the boson-impurity interaction strength. Our focus is on the effects of inhomogeneity due to the harmonic confinement. These effects can be described by an effective one-body model where both the mass and the spring constant are renormalized. This is in contrast to the classic renormalization, which addresses only the mass. We propose an effective single-particle Hamiltonian and apply the multi-layer multi-configuration time-dependent Hartree method for bosons to explore its validity. Numerical results suggest that the effective mass is smaller than the impurity mass, which means that it cannot straightforwardly be extracted from translationally-invariant models.arXiv:1809.01889v3 [cond-mat.quant-gas]

show abstract

Section: A Case With C < Gmentioning

confidence: 98%

Effective approach to impurity dynamics in one-dimensional trapped Bose gases

et al. 2019

View full text Add to dashboard Cite

show abstract

“…, is called fragmentation. From the definition, it is clear that one needs more than one orbital to study the depletion and fragmentation and hence, these quantities can only be studied by at least a two-orbital (many-body) theory [103,104] and preferably a multi-orbital (many-body) theory [51,97,105]. We remark that the depletion of a BEC is usually small and may not have a prominent effect on the density per particle and energy per particle which, in effect, can be accurately described by a mean-field theory.…”

Section: B2 Physical Quantitiesmentioning

confidence: 99%

Many-body quantum dynamics of an asymmetric bosonic Josephson junction

Haldar

Alon

2019

New J. Phys.

View full text Add to dashboard Cite

The out-of-equilibrium quantum dynamics of an interacting Bose gas trapped in a one-dimensional asymmetric double-well potential is studied by solving the many-body Schrödinger equation numerically accurately. We examine how the gradual loss of symmetry of the confining trap affects the macroscopic quantum tunneling dynamics of the system between the two wells. In an asymmetric double well, the two wells are not equivalent anymore, say, the left well is deeper than the right one. Accordingly, we analyze the dynamics by initially preparing the condensate in both the left and the right wells. The dynamics of the system is characterized by the time evolution of a few physical quantities of increasing many-body complexity, namely, the survival probability, depletion and fragmentation, and the many-particle position and momentum variances. In particular, we have examined the frequencies and amplitudes of the oscillations of the survival probabilities, the time scale for the development of fragmentation and its degree, and the growth and oscillatory behavior of the many-particle position and momentum variances. There is an overall suppression of the oscillations of the survival probabilities in an asymmetric double well, except for resonant values of asymmetry for which the one-body ground state energy in the right well matches with one of the one-body excited states in the left well, thereby resulting in resonantly enhanced tunneling from the right well ground state. Overall, depending on whether the condensate is initially prepared in the left or right well, the repulsive inter-atomic interactions affect the survival probabilities differently. For a sufficiently strong repulsive interaction, the system is found to become fragmented. The degree of fragmentation depends both on the asymmetry of the trap and the initial well in which the condensate is prepared in a non-trivial manner. Furthermore, we show that the phenomenon of resonantly enhanced tunneling can be accompanied by a large degree of fragmentation (depletion) for the strong (weak) interaction. The many-particle position and momentum variances follow the density oscillations of the system in the asymmetric double well and bears prominent signatures of the degree of depletion or fragmentation, depending on the strength of the interactions. These quantities further exhibit a fine structure signifying a breathing-mode oscillation. Finally, a universality of fragmentation for systems made of different numbers of particles but the same interaction parameter is also found and its dependence on the asymmetry is investigated. The phenomenon is robust despite the asymmetry of the junction and admits a macroscopically-large fragmented condensate characterized by a diverging many-particle position variance. This is as far as one can get from the dynamics of the density in the junction.recently. This has opened a whole new research field of strongly correlated systems with potential applications in quantum technology and quantum simulation of condensed-matter problems [...

show abstract

“…We emphasize that this simple analysis does not thoroughly justify the two-mode truncation of the field operator expansion. A more complete analysis determining in particular the energy level occupation statistics must involve self-consistent many-body calculations cf., e.g., the multiconfigurational Hartree approach utilized in [56,58].…”

Section: A System Hamiltonian and Ground Statesmentioning

confidence: 99%

Many-body quantum metrology with scalar bosons in a single potential well

2019

Self Cite

View full text Add to dashboard Cite

We theoretically investigate the possibility of performing high precision estimation of an externally imposed acceleration using scalar bosons in a single-well trap. We work at the level of a two-mode truncation, valid for weak to intermediate two-body interaction couplings. The splitting process into two modes is in our model entirely caused by the interaction between the constituent bosons and is hence neither due to an externally imposed double-well potential nor due to populating a spinor degree of freedom. The precision enhancement gained by using various initial quantum states using a two-mode bosonic system is well established. Here we therefore instead focus on the effect of the intrinsic dynamics on the precision, where, in a single well, the Hamiltonian assumes a form different from that of the typical double-well case. We demonstrate how interactions can significantly increase the quantum Fisher information maximized over initial states as well as the quantum Fisher information for a fragmented or a coherent state, the two many-body states that can commonly represent the ground state of our system.

show abstract

Self-consistent determination of the many-body state of ultracold bosonic atoms in a one-dimensional harmonic trap

Cited by 10 publications

References 60 publications

Effective approach to impurity dynamics in one-dimensional trapped Bose gases

Effective approach to impurity dynamics in one-dimensional trapped Bose gases

Many-body quantum dynamics of an asymmetric bosonic Josephson junction

Many-body quantum metrology with scalar bosons in a single potential well

Contact Info

Product

Resources

About