Ultracold Dipolar Gases ? a Challenge for Experiments and Theory

Baranov, M. A.; Dobrek, Ł.; G?ral, K.; Santos, Luís; Lewenstein, Maciej

doi:10.1238/physica.topical.102a00074

Cited by 143 publications

(114 citation statements)

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“…Perhaps most importantly, dipolar molecules interact with one another much more strongly and at longer range than atoms. Dipolar molecules have been proposed as qubits for quantum computers [17] and dipolar quantum gases are predicted to exhibit a range of novel features [18].…”

Section: Introductionmentioning

confidence: 99%

Molecular collisions in ultracold atomic gases

Hutson

Soldán

2007

International Reviews in Physical Chemistry

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It has recently become possible to form molecules in ultracold gases of trapped alkali metal atoms. Once formed, the molecules may undergo elastic, inelastic and reactive collisions. Inelastic and reactive collisions are particularly important because they release kinetic energy and eject atoms and molecules from the trap. The theory needed to handle such collisions is presented and recent quantum dynamics calculations on ultracold atom-diatom collisions of spin-polarised Li + Li2, Na + Na2 and K + K2 are described. All these systems have potential energy surfaces on which barrierless atom exchange reactions can occur, and both inelastic and reactive rates are very fast (typically k inel > 10 −10 cm 3 s −1 in the Wigner regime).

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Section: Introductionmentioning

confidence: 99%

Molecular collisions in ultracold atomic gases

Hutson

Soldán

2007

International Reviews in Physical Chemistry

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“…Promising proposals to tune and shape the dipolar interaction strength in quantum gasees of heteronuclear polar molecules have more recently been suggested [10]. Significant theoretical predictions have accompanied such realizations [11]. The stability diagram of anisotropic confined dipolar gases has been predicted to be governed by the trapping geometry [12,13], as corroborated by Path-Integral QMC studies [14].…”

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confidence: 99%

Evidence of Luttinger-liquid behavior in one-dimensional dipolar quantum gases

et al. 2007

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The ground state and structure of a one-dimensional Bose gas with dipolar repulsions is investigated at zero temperature by a combined Reptation Quantum Monte Carlo (RQMC) and bosonization approach. A non trivial Luttinger-liquid behavior emerges in a wide range of intermediate densities, evolving into a Tonks-Girardeau gas at low density and into a classical quasi-ordered state at high density. The density dependence of the Luttinger exponent is extracted from the numerical data, providing analytical predictions for observable quantities, such as the structure factor and the momentum distribution. We discuss the accessibility of such predictions in current experiments with ultracold atomic and molecular gases. More recent experiments have demonstrated that the range of the interactions can also be manipulated. Dipole interactions with long-range anisotropic character have been observed in 52 Cr atoms [7] after exploiting the large magnetic moments of this atomic species, that is µ d ≈ 6µ B with µ B being the Bohr magneton. A BEC containing up to 50000 52 Cr atoms has then been obtained below a transition temperature T c ≃ 700nK [8] and its dynamical behavior is being investigated [9]. Promising proposals to tune and shape the dipolar interaction strength in quantum gasees of heteronuclear polar molecules have more recently been suggested [10]. Significant theoretical predictions have accompanied such realizations [11]. The stability diagram of anisotropic confined dipolar gases has been predicted to be governed by the trapping geometry [12,13], as corroborated by Path-Integral QMC studies [14]. Different conclusions are reached by more recent Diffusion QMC simulations including the dependence of a on the dipole interaction [15]. PACSTuning of the interactions can be combined with the enhancement of quantum fluctuations after reducing their dimensionality by e.g. storing them in elongated traps [16,17], which could be relevant to applications such as precision measurements [18], quantum computing [19], atomtronic quantum devices, and theoretical investigations of novel quantum phase transitions [20].In the case of quasi one-dimensional (1D) condensates with short-range interactions, a rich phenomenology is known to emerge from the collective character of the single-particle degrees of freedom, despite the absence of broken symmetries [21]. Bosons are known to arrange in a Luttingerliquid state, with single particles being replaced by collective density excitations [22,23]. Strong repulsion may also lead to the fermionization of interacting bosons in the so-called Tonks-Girardeau (TG) regime [24,25,26]. Experiments in elongated traps have provided evidence for such 1D fluctuations [16].In the case of quasi-1D condensates with dipolar interactions, an interesting question arises whether the quantum fluctuations are sufficiently enhanced to drive the BEC in a strong-coupling regime. More recent Diffusion QMC simulations [27] for a homogeneous 1D dipolar Bose gas have revealed a crossover behavior with increasing li...

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“…Atomic molybdenum has several features that make it an interesting candidate for an ultracold gas. Because of its large magnetic moment (6 Bohr magneton), the dipolar and van der Waals mean-field energies will be similar in a Mo Bose condensate, perhaps leading to new observable dipolar effects [1][2][3][4][5]. Mo has several stable isotopes, 2 fermions and 5 bosons.…”

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confidence: 99%