Quantum states of Bose-Einstein condensates formed by molecular dissociation

Poulsen, Uffe V.; Mølmer, Klaus

doi:10.1103/physreva.63.023604

Cited by 56 publications

(64 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When performed using a molecular BoseEinstein condensate (BEC) as the initial state and assuming that the constituent atoms are bosons, the process lends itself [16][17][18][19] as a direct matter-wave analog of optical parametric down-conversion of an intense laser light in a χ (2) -nonlinear crystal. Owing to this analogy, one can envisage that future experiments on dissociation of molecular BECs can lead to atom optics demonstrations of EPR correlations [20][21][22] and related tests of Bell's inequalities [23,24].…”

Section: Introductionmentioning

confidence: 99%

Role of spatial inhomogeneity in dissociation of trapped molecular condensates

Ögren

Kheruntsyan

2010

Phys. Rev. A

View full text Add to dashboard Cite

We theoretically analyze dissociation of a harmonically trapped Bose-Einstein condensate of molecular dimers and examine how the spatial inhomogeneity of the molecular condensate affects the conversion dynamics and the atom-atom pair correlations in the short-time limit. Both fermionic and bosonic statistics of the constituent atoms are considered. Using the undepleted molecular-field approximation, we obtain explicit analytic results for the asymptotic behavior of the second-order correlation functions and for the relative number squeezing between the dissociated atoms in one, two, and three spatial dimensions. Comparison with the numerical results shows that the analytic approach employed here captures the main underlying physics and provides useful insights into the dynamics of dissociation for conversion efficiencies up to 10%. The results show explicitly how the strength of atom-atom correlations and relative number squeezing degrade with the reduction of the size of the molecular condensate.

show abstract

Section: Introductionmentioning

confidence: 99%

Role of spatial inhomogeneity in dissociation of trapped molecular condensates

Ögren

Kheruntsyan

2010

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…Finally, in a broader context, one expects other situations that generate a scattered atom halo, such as molecular dissociation in a condensate [36,37,[42][43][44][45][46][47][48], atomic parametric down-conversion [4,[49][50][51][52][53], or the interaction of a condensate with barriers and obstacles [54][55][56][57][58], to also be susceptible to the same anisotropy-producing processes. …”

Section: Discussionmentioning

confidence: 99%

Anisotropy ins-wave Bose-Einstein condensate collisions and its relationship to superradiance

et al. 2014

View full text Add to dashboard Cite

We report the experimental realization of a single-species atomic four-wave mixing process with BoseEinstein-condensate collisions for which the angular distribution of scattered atom pairs is not isotropic, despite the collisions being in the s-wave regime. Theoretical analysis indicates that this anomalous behavior can be explained by the anisotropic nature of the gain in the medium. There are two competing anisotropic processes: classical trajectory deflections due to the mean-field potential and Bose-enhanced scattering which bears similarity to superradiance. We analyze the relative importance of these processes in the dynamical buildup of the anisotropic density distribution of scattered atoms and compare the Bose enhancement effects to those in optically pumped superradiance.

show abstract

“…Interestingly enough, rather than the binomial distribution of particles obtained for dual atomic condensates [14], the trilinear free-bound interaction leads to a squeezed atom-molecule condensate. Such squeezing occurs exactly as in SHG [8], and is a source of many-particle entanglement [22,32].…”

Section: Pacs Number(s)mentioning

confidence: 99%

“…Besides the strongly enhanced efficiency of molecule formation [18,19], which actually relies on an order-unity phase-space density rather than coherence [19], recent theoretical investigations into photoassociation of a BEC have led to a variety of phenomena involving macroscopic quantum coherence. For example, there are predictions of coherent molecular solitons [16], rapid [17] and Raman [20] adiabatic passage from an atomic to a molecular condensate, Josephson-like BEC-MBEC oscillations [16,17,21], and squeezed atomic condensates formed from an initial MBEC [22].…”

Section: Pacs Number(s)mentioning

confidence: 99%

Superposition of Macroscopic Numbers of Atoms and Molecules

2001

View full text Add to dashboard Cite

We theoretically examine photoassociation of a non-ideal Bose-Einstein condensate, focusing on evidence for a macroscopic superposition of atoms and molecules. This problem raises an interest because, rather than two states of a given object, an atom-molecule system is a seemingly impossible macroscopic superposition of different objects. Nevertheless, photoassociation enables coherent intraparticle conversion, and we thereby propose a viable scheme for creating a superposition of a macroscopic number of atoms with a macroscopic number of molecules. PACS number(s): 03.75. Fi, 03.65.Bz, 32.80.Wr In a now famous gedanken experiment [1], Schrödinger highlighted the absurdity of applying quantum theory to macroscopic objects by coupling the fate of a cat to the decay of a radioactive atom, thereby forcing the animal into a superposition of alive and dead. Over the years, this nefarious situation has come to mark the fundamental difference of principle between microscopic quantum mechanics and macroscopic realism: whereas the latter asserts that a system with two (or more) macroscopically distinct states must be in one or the other of these states, the former of course allows for superpositions of different states [2]. It is, however, a somewhat subtle point that marks the difference between macroscopic coherence and a macroscopic superposition. Given a collection of N two-level systems, the macroscopic coherence that leads, e.g., to Josephson-like oscillations, where all N systems tunnel in tandem between the two states, requires only that each system is in a coherent superposition of the two levels, whereas a macroscopic superposition with all of the systems in one or the other of the two states necessarily exhibits an N -body coherence [15]. It is exactly this distinction that warrants the present investigation. Beyond the usual macroscopic superposition of two states of a given object, photoassociation actually leads to a more counterintuitive situation since, like (say) protons and quarks, molecules and atoms are different objects. To the best of our knowledge, the only contemporary systems with a similar potential are a BEC tuned to a Feshbach resonance [23], which would also give a macroscopic atom-molecule superposition, and secondharmonic generation [24] (SHG), which would create, for example, a macroscopic superposition of red and blue photons. These three systems are of course mathematically identical, and the subsequent intramode superposition lies in the possibility for coherent atom-molecule (red-blue photon) conversion. So far, SHG has only yielded intramode phase superpositions between coherent states [9,25], but these results are somewhat ambiguous as they do not differentiate between a coherent superposition and a statistical mixture. In contrast, the present work, based on unitary evolution of a Fock state, clearly demonstrates an intramode superposition of a macroscopic number of atoms with a macroscopic number of molecules. With photoassociation currently [26] on the verge [27] of coherence, t...

show abstract

Quantum states of Bose-Einstein condensates formed by molecular dissociation

Cited by 56 publications

References 45 publications

Role of spatial inhomogeneity in dissociation of trapped molecular condensates

Role of spatial inhomogeneity in dissociation of trapped molecular condensates

Anisotropy ins-wave Bose-Einstein condensate collisions and its relationship to superradiance

Superposition of Macroscopic Numbers of Atoms and Molecules

Contact Info

Product

Resources

About