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Doublon dynamics and polar molecule production in an optical lattice.

Covey JP, Moses SA, Gärttner M, Safavi-Naini A, Miecnikowski MT, Fu Z, Schachenmayer J, Julienne PS, Rey AM, Jin DS, Ye J - Nat Commun (2016)

Bottom Line: Here we use such a system to prepare a density distribution where lattice sites are either empty or occupied by a doublon composed of an interacting Bose-Fermi pair.Additionally, we can probe the distribution of the atomic gases in the lattice by measuring the inelastic loss of doublons.These techniques realize tools that are generically applicable to studying the complex dynamics of atomic mixtures in optical lattices.

View Article: PubMed Central - PubMed

Affiliation: JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309, USA.

ABSTRACT
Polar molecules in an optical lattice provide a versatile platform to study quantum many-body dynamics. Here we use such a system to prepare a density distribution where lattice sites are either empty or occupied by a doublon composed of an interacting Bose-Fermi pair. By letting this out-of-equilibrium system evolve from a well-defined, but disordered, initial condition, we observe clear effects on pairing that arise from inter-species interactions, a higher partial-wave Feshbach resonance and excited Bloch-band population. These observations facilitate a detailed understanding of molecule formation in the lattice. Moreover, the interplay of tunnelling and interaction of fermions and bosons provides a controllable platform to study Bose-Fermi Hubbard dynamics. Additionally, we can probe the distribution of the atomic gases in the lattice by measuring the inelastic loss of doublons. These techniques realize tools that are generically applicable to studying the complex dynamics of atomic mixtures in optical lattices.

No MeSH data available.


Related in: MedlinePlus

Longer time dynamics.The dependence of the doublon fraction on the hold time  in the lattice for both 10ER (green circles and squares) and 15ER (blue diamonds and triangles) for either aK-Rb=−1,900a0 (circles, diamonds) or aK-Rb=−1,900a0 (squares, triangles). The lines are fits to an exponential decay and are intended only as guides to the eye. (Inset) The doublon decay can involve tunnelling of doublons through empty sites (i) prior to loss by the Rb tunnelling process illustrated in (ii). All error bars represent 1−σ standard error.
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f4: Longer time dynamics.The dependence of the doublon fraction on the hold time in the lattice for both 10ER (green circles and squares) and 15ER (blue diamonds and triangles) for either aK-Rb=−1,900a0 (circles, diamonds) or aK-Rb=−1,900a0 (squares, triangles). The lines are fits to an exponential decay and are intended only as guides to the eye. (Inset) The doublon decay can involve tunnelling of doublons through empty sites (i) prior to loss by the Rb tunnelling process illustrated in (ii). All error bars represent 1−σ standard error.

Mentions: In Fig. 4, we present data taken for up to 40 ms, in order to look for the effects of Rb tunnelling. Measurements of the remaining doublon fraction are shown for two lattice depths (10ER and 15ER) and two values of aK-Rb (−910a0 and −1900a0). In Fig. 4, the doublon fraction has been normalized by the measured value for in order to remove the effect of the shorter-time dynamics that are presented in Fig. 3a,b. Similar to the shorter-time dynamics, at the longer hold times we observe a reduction in the doublon fraction that is suppressed for a deeper lattice and for strong inter-species interactions. Modeling these dynamics is theoretically challenging, and the lines in Fig. 4 are exponential fits that are intended only as guides to the eye. Compared to doublons composed of identical bosons13 or fermions in two-spin states30, the heteronuclear system has the additional complexities of two particle masses, two tunnelling rates and two relevant interaction energies. For example, for large aK-Rb, the interspecies interactions will strongly suppress Rb tunnelling from a doublon to a neighbouring empty site. Similarly, tunnelling of a doublon to an empty lattice site is a slow second-order process at the rate due to the energy gap of (Fig. 4 inset i). However, Rb tunnelling between two neighbouring doublons, which creates a triplon (Rb-Rb-K) on one site and a lone K atom on the other site (Fig. 4 inset ii), may occur on a faster time scale due to a much smaller energy gap of , which is smaller than the K tunnelling bandwidth. While the theoretical description is complicated, we observe that the time scale of the doublon decay roughly matches .


Doublon dynamics and polar molecule production in an optical lattice.

Covey JP, Moses SA, Gärttner M, Safavi-Naini A, Miecnikowski MT, Fu Z, Schachenmayer J, Julienne PS, Rey AM, Jin DS, Ye J - Nat Commun (2016)

Longer time dynamics.The dependence of the doublon fraction on the hold time  in the lattice for both 10ER (green circles and squares) and 15ER (blue diamonds and triangles) for either aK-Rb=−1,900a0 (circles, diamonds) or aK-Rb=−1,900a0 (squares, triangles). The lines are fits to an exponential decay and are intended only as guides to the eye. (Inset) The doublon decay can involve tunnelling of doublons through empty sites (i) prior to loss by the Rb tunnelling process illustrated in (ii). All error bars represent 1−σ standard error.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834636&req=5

f4: Longer time dynamics.The dependence of the doublon fraction on the hold time in the lattice for both 10ER (green circles and squares) and 15ER (blue diamonds and triangles) for either aK-Rb=−1,900a0 (circles, diamonds) or aK-Rb=−1,900a0 (squares, triangles). The lines are fits to an exponential decay and are intended only as guides to the eye. (Inset) The doublon decay can involve tunnelling of doublons through empty sites (i) prior to loss by the Rb tunnelling process illustrated in (ii). All error bars represent 1−σ standard error.
Mentions: In Fig. 4, we present data taken for up to 40 ms, in order to look for the effects of Rb tunnelling. Measurements of the remaining doublon fraction are shown for two lattice depths (10ER and 15ER) and two values of aK-Rb (−910a0 and −1900a0). In Fig. 4, the doublon fraction has been normalized by the measured value for in order to remove the effect of the shorter-time dynamics that are presented in Fig. 3a,b. Similar to the shorter-time dynamics, at the longer hold times we observe a reduction in the doublon fraction that is suppressed for a deeper lattice and for strong inter-species interactions. Modeling these dynamics is theoretically challenging, and the lines in Fig. 4 are exponential fits that are intended only as guides to the eye. Compared to doublons composed of identical bosons13 or fermions in two-spin states30, the heteronuclear system has the additional complexities of two particle masses, two tunnelling rates and two relevant interaction energies. For example, for large aK-Rb, the interspecies interactions will strongly suppress Rb tunnelling from a doublon to a neighbouring empty site. Similarly, tunnelling of a doublon to an empty lattice site is a slow second-order process at the rate due to the energy gap of (Fig. 4 inset i). However, Rb tunnelling between two neighbouring doublons, which creates a triplon (Rb-Rb-K) on one site and a lone K atom on the other site (Fig. 4 inset ii), may occur on a faster time scale due to a much smaller energy gap of , which is smaller than the K tunnelling bandwidth. While the theoretical description is complicated, we observe that the time scale of the doublon decay roughly matches .

Bottom Line: Here we use such a system to prepare a density distribution where lattice sites are either empty or occupied by a doublon composed of an interacting Bose-Fermi pair.Additionally, we can probe the distribution of the atomic gases in the lattice by measuring the inelastic loss of doublons.These techniques realize tools that are generically applicable to studying the complex dynamics of atomic mixtures in optical lattices.

View Article: PubMed Central - PubMed

Affiliation: JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309, USA.

ABSTRACT
Polar molecules in an optical lattice provide a versatile platform to study quantum many-body dynamics. Here we use such a system to prepare a density distribution where lattice sites are either empty or occupied by a doublon composed of an interacting Bose-Fermi pair. By letting this out-of-equilibrium system evolve from a well-defined, but disordered, initial condition, we observe clear effects on pairing that arise from inter-species interactions, a higher partial-wave Feshbach resonance and excited Bloch-band population. These observations facilitate a detailed understanding of molecule formation in the lattice. Moreover, the interplay of tunnelling and interaction of fermions and bosons provides a controllable platform to study Bose-Fermi Hubbard dynamics. Additionally, we can probe the distribution of the atomic gases in the lattice by measuring the inelastic loss of doublons. These techniques realize tools that are generically applicable to studying the complex dynamics of atomic mixtures in optical lattices.

No MeSH data available.


Related in: MedlinePlus