arXiv:cond-mat/0301159 · Physical Review Letters

Magnetic Control of the Interaction in Ultracold K-Rb Mixtures

Andrea Simoni, Francesca Ferlaino, G. Roati, Giovanni Carlo Modugno, M. Inguscio

Published Apr 23, 2003• 129 citations

Abstract

We predict the presence of several magnetic Feshbach resonances in selected Zeeman sublevels of the isotopic pairs $^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}$ and $^{41}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}$ at magnetic fields up to ${10}^{3}\text{ }\mathrm{G}$. Positions and widths are determined combining a new measurement of the $^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}$ inelastic cross section with recent experimental results on both isotopes. The possibility of driving a K-Rb mixture from the weak to the strong interacting regime tuning the applied field should allow one to achieve the optimal conditions for boson-induced Cooper pairing in a multicomponent $^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}$ atomic gas and for the production of ultracold polar molecules.

DOI: 10.1103/physrevlett.90.163202

Related papers

Feshbach spectroscopy of a K−Rb atomic mixture

Francesca Ferlaino, Chiara D’Errico, G. Roati +4 more

arXiv:cond-mat/0510630Physical Review AApr 14, 2006161 citations

Feshbach resonances and molecule formation in ultracold mixtures of Rb and Yb(P3) atoms

Bijit Mukherjee, Matthew D. Frye, Jeremy M. Hutson

arXiv:2110.15906Physical Review AFeb 7, 20226 citations

Feshbach resonances in ultracold Rb 85 − Rb 87 and Li 6 − Rb 87 mixtures

Z. Li, S. Singh, Timur V. Tscherbul +1 more

arXiv:0807.0417Physical Review AAug 29, 200848 citations

Feshbach resonances in an ultracold mixture of87Rb and40K

Pengjun Wang, Zhengkun Fu, Shijie Chai +1 more

Chinese Physics BOct 1, 201110 citations

Observation of Heteronuclear Feshbach Resonances in a Mixture of Bosons and Fermions

S. Inouye, J. Goldwin, M. L. Olsen +3 more

arXiv:cond-mat/0406208Physical Review LettersOct 25, 2004307 citations

Observation of Feshbach resonances between ultracold Na and Rb atoms

Fudong Wang, Dezhi Xiong, Xiaoke Li +2 more

arXiv:1303.0334Physical Review AMay 30, 201352 citations

arXiv:cond-mat/0301159 · Physical Review Letters

Magnetic Control of the Interaction in Ultracold K-Rb Mixtures

Andrea Simoni, Francesca Ferlaino, G. Roati, Giovanni Carlo Modugno, M. Inguscio

Published Apr 23, 2003• 129 citations

arXiv HTML PDF

Abstract

We predict the presence of several magnetic Feshbach resonances in selected Zeeman sublevels of the isotopic pairs

^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}

and

^{41}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}

at magnetic fields up to

{10}^{3}\text{ }\mathrm{G}

. Positions and widths are determined combining a new measurement of the

^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}

inelastic cross section with recent experimental results on both isotopes. The possibility of driving a K-Rb mixture from the weak to the strong interacting regime tuning the applied field should allow one to achieve the optimal conditions for boson-induced Cooper pairing in a multicomponent

^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}

atomic gas and for the production of ultracold polar molecules.

DOI: 10.1103/physrevlett.90.163202

Related papers

Feshbach spectroscopy of a K−Rb atomic mixture

Francesca Ferlaino, Chiara D’Errico, G. Roati +4 more

We perform extensive magnetic Feshbach spectroscopy of an ultracold mixture of fermionic $^{40}\mathrm{K}$ and bosonic $^{87}\mathrm{Rb}$ atoms. The magnetic-field locations of 13 interspecies resonances are used to construct a quantum collision model able to predict accurate collisional parameters for all $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. In particular, we determine the interspecies $s$ -wave singlet and triplet scattering lengths for the $^{40}\mathrm{K}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixture as $(\ensuremath{-}108\ifmmode\pm\else\textpm\fi{}3){a}_{0}$ and $(\ensuremath{-}205\ifmmode\pm\else\textpm\fi{}5){a}_{0}$, respectively. We also predict accurate scattering lengths and the position of Feshbach resonances for the other $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. We discuss the consequences of our results for current and future experiments with ultracold $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ mixtures.We perform extensive magnetic Feshbach spectroscopy of an ultracold mixture of fermionic $^{40}\mathrm{K}$ and bosonic $^{87}\mathrm{Rb}$ atoms. The magnetic-field locations of 13 interspecies resonances are used to construct a quantum collision model able to predict accurate collisional parameters for all $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. In particular, we determine the interspecies $s$-wave singlet and triplet scattering lengths for the $^{40}\mathrm{K}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixture as $(\ensuremath{-}108\ifmmode\pm\else\textpm\fi{}3){a}_{0}$ and $(\ensuremath{-}205\ifmmode\pm\else\textpm\fi{}5){a}_{0}$, respectively. We also predict accurate scattering lengths and the position of Feshbach resonances for the other $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. We discuss the consequences of our results for current and future experiments with ultracold $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ mixtures.

arXiv:cond-mat/0510630Physical Review AApr 14, 2006161 citations

Feshbach resonances and molecule formation in ultracold mixtures of Rb and Yb(P3) atoms

Bijit Mukherjee, Matthew D. Frye, Jeremy M. Hutson

We have investigated magnetically tunable Feshbach resonances in ultracold collisions of Rb with Yb in its metastable ${}^{3}{P}_{2}$ and ${}^{3}{P}_{0}$ states, using coupled-channel scattering and bound-state calculations. For the ${}^{3}{P}_{2}$ state, we find sharp resonances when both atoms are in their lowest Zeeman sublevels. However, these resonances are decayed by inelastic processes that produce Yb atoms in ${}^{3}{P}_{1}$ and ${}^{3}{P}_{0}$ states. The molecules that might be produced by magnetoassociation at the ${}^{3}{P}_{2}$ thresholds can decay by similar pathways and would have lifetimes no more than a few microseconds. For the ${}^{3}{P}_{0}$ state, by contrast, there are resonances that are promising for magnetoassociation. There are resonances due to both rotating and nonrotating molecular states that are significantly stronger than the analogous resonances for $\mathrm{Yb}{(}^{1}S$ ). The ones due to rotating states are denser in magnetic field; in contrast to $\mathrm{Yb}{(}^{1}S$ ), they exist even for bosonic isotopes of $\mathrm{Yb}{(}^{3}{P}_{0}$ ).We have investigated magnetically tunable Feshbach resonances in ultracold collisions of Rb with Yb in its metastable ${}^{3}{P}_{2}$ and ${}^{3}{P}_{0}$ states, using coupled-channel scattering and bound-state calculations. For the ${}^{3}{P}_{2}$ state, we find sharp resonances when both atoms are in their lowest Zeeman sublevels. However, these resonances are decayed by inelastic processes that produce Yb atoms in ${}^{3}{P}_{1}$ and ${}^{3}{P}_{0}$ states. The molecules that might be produced by magnetoassociation at the ${}^{3}{P}_{2}$ thresholds can decay by similar pathways and would have lifetimes no more than a few microseconds. For the ${}^{3}{P}_{0}$ state, by contrast, there are resonances that are promising for magnetoassociation. There are resonances due to both rotating and nonrotating molecular states that are significantly stronger than the analogous resonances for $\mathrm{Yb}{(}^{1}S$). The ones due to rotating states are denser in magnetic field; in contrast to $\mathrm{Yb}{(}^{1}S$), they exist even for bosonic isotopes of $\mathrm{Yb}{(}^{3}{P}_{0}$).

arXiv:2110.15906Physical Review AFeb 7, 20226 citations

Feshbach resonances in ultracold Rb 85 − Rb 87 and Li 6 − Rb 87 mixtures

Z. Li, S. Singh, Timur V. Tscherbul +1 more

We present an analysis of experimentally accessible magnetic Feshbach resonances in ultracold heteronuclear $^{85}\mathrm{Rb}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ and $^{6}\mathrm{Li}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixtures. Using recent experimental measurements of the triplet scattering lengths for $^{6}\mathrm{Li}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ and $^{7}\mathrm{Li}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixtures and Feshbach resonances for one combination of atomic states, we create model potential curves and fine-tune them to reproduce the measured resonances and to predict the location of several experimentally relevant resonances in Li-Rb collisions. To model $^{85}\mathrm{Rb}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ collisions, we use accurate ${\mathrm{Rb}}_{2}$ potentials obtained previously from the analysis of experiments on $^{87}\mathrm{Rb}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ collisions. We find resonances that occur at very low magnetic fields, below $10\phantom{\rule{0.3em}{0ex}}\mathrm{G}$ , which may be useful for entanglement generation in optical lattices or atom chip magnetic traps.We present an analysis of experimentally accessible magnetic Feshbach resonances in ultracold heteronuclear $^{85}\mathrm{Rb}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ and $^{6}\mathrm{Li}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixtures. Using recent experimental measurements of the triplet scattering lengths for $^{6}\mathrm{Li}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ and $^{7}\mathrm{Li}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixtures and Feshbach resonances for one combination of atomic states, we create model potential curves and fine-tune them to reproduce the measured resonances and to predict the location of several experimentally relevant resonances in Li-Rb collisions. To model $^{85}\mathrm{Rb}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ collisions, we use accurate ${\mathrm{Rb}}_{2}$ potentials obtained previously from the analysis of experiments on $^{87}\mathrm{Rb}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ collisions. We find resonances that occur at very low magnetic fields, below $10\phantom{\rule{0.3em}{0ex}}\mathrm{G}$, which may be useful for entanglement generation in optical lattices or atom chip magnetic traps.

arXiv:0807.0417Physical Review AAug 29, 200848 citations

Feshbach resonances in an ultracold mixture of87Rb and40K

Pengjun Wang, Zhengkun Fu, Shijie Chai +1 more

We report the experimental preparations of the absolute ground states of 87 Rb and 40 K atoms (| F = 1, m F = 1〉 + | F = 9/2, m F = −9/2〉) by means of the radio-frequency and microwave adiabatic rapid passages, and the observation of magnetic Feshbach resonances in an ultracold mixture of bosonic 87 Rb and fermionic 40 K atoms between 0 T and 6.0 × 10 −2 T, including 7 homonuclear and 4 heteronuclear Feshbach resonances. The resonances are identified by the abrupt trap loss of atoms induced by the strong inelastic three-body collisions. These Feshbach resonances should enable the experimental control of interspecies interactions.We report the experimental preparations of the absolute ground states of 87 Rb and 40 K atoms (| F = 1, m F = 1〉 + | F = 9/2, m F = −9/2〉) by means of the radio-frequency and microwave adiabatic rapid passages, and the observation of magnetic Feshbach resonances in an ultracold mixture of bosonic 87 Rb and fermionic 40 K atoms between 0 T and 6.0 × 10 −2 T, including 7 homonuclear and 4 heteronuclear Feshbach resonances. The resonances are identified by the abrupt trap loss of atoms induced by the strong inelastic three-body collisions. These Feshbach resonances should enable the experimental control of interspecies interactions.

Chinese Physics BOct 1, 201110 citations

Observation of Heteronuclear Feshbach Resonances in a Mixture of Bosons and Fermions

S. Inouye, J. Goldwin, M. L. Olsen +3 more

Three magnetic-field induced heteronuclear Feshbach resonances were identified in collisions between bosonic $^{87}\mathrm{R}\mathrm{b}$ and fermionic $^{40}\mathrm{K}$ atoms in their absolute ground states. Strong inelastic loss from an optically trapped mixture was observed at the resonance positions of 492, 512, and $543\ifmmode\pm\else\textpm\fi{}2\text{ }\text{ }\mathrm{G}$. The magnetic-field locations of these resonances place a tight constraint on the triplet and singlet cross-species scattering lengths, yielding $(\ensuremath{-}281\ifmmode\pm\else\textpm\fi{}15){a}_{0}$ and $(\ensuremath{-}54\ifmmode\pm\else\textpm\fi{}12){a}_{0}$, respectively. The width of the loss feature at 543 G is $3.7\ifmmode\pm\else\textpm\fi{}1.5\text{ }\text{ }\mathrm{G}$ wide; this broad Feshbach resonance should enable experimental control of the interspecies interactions.Three magnetic-field induced heteronuclear Feshbach resonances were identified in collisions between bosonic $^{87}\mathrm{R}\mathrm{b}$ and fermionic $^{40}\mathrm{K}$ atoms in their absolute ground states. Strong inelastic loss from an optically trapped mixture was observed at the resonance positions of 492, 512, and $543\ifmmode\pm\else\textpm\fi{}2\text{ }\text{ }\mathrm{G}$. The magnetic-field locations of these resonances place a tight constraint on the triplet and singlet cross-species scattering lengths, yielding $(\ensuremath{-}281\ifmmode\pm\else\textpm\fi{}15){a}_{0}$ and $(\ensuremath{-}54\ifmmode\pm\else\textpm\fi{}12){a}_{0}$, respectively. The width of the loss feature at 543 G is $3.7\ifmmode\pm\else\textpm\fi{}1.5\text{ }\text{ }\mathrm{G}$ wide; this broad Feshbach resonance should enable experimental control of the interspecies interactions.

arXiv:cond-mat/0406208Physical Review LettersOct 25, 2004307 citations

Observation of Feshbach resonances between ultracold Na and Rb atoms

Fudong Wang, Dezhi Xiong, Xiaoke Li +2 more

We have successfully prepared an optically trapped ultracold mixture of ${}^{23}$ Na and ${}^{87}$ Rb atoms and studied their interspecies Feshbach resonances. Using two different spin combinations, several $s$ - and $p$ -wave resonances are identified by observing high inelastic losses and temperature increases for both species near resonant magnetic field values. The two $s$ -wave resonances observed below 500 G between atoms in their lowest-energy levels are possible candidates for Feshbach molecule association. Our results are well characterized by a coupled-channel model which also refines the ground-state interaction potentials between ${}^{23}$ Na and ${}^{87}$ Rb. This work opens up the prospect for preparing ultracold ensembles of ground-state bosonic NaRb molecules which are chemically stable and can provide strong dipolar interactions.We have successfully prepared an optically trapped ultracold mixture of ${}^{23}$Na and ${}^{87}$Rb atoms and studied their interspecies Feshbach resonances. Using two different spin combinations, several $s$- and $p$-wave resonances are identified by observing high inelastic losses and temperature increases for both species near resonant magnetic field values. The two $s$-wave resonances observed below 500 G between atoms in their lowest-energy levels are possible candidates for Feshbach molecule association. Our results are well characterized by a coupled-channel model which also refines the ground-state interaction potentials between ${}^{23}$Na and ${}^{87}$Rb. This work opens up the prospect for preparing ultracold ensembles of ground-state bosonic NaRb molecules which are chemically stable and can provide strong dipolar interactions.

arXiv:1303.0334Physical Review AMay 30, 201352 citations

We predict the presence of several magnetic Feshbach resonances in selected Zeeman sublevels of the isotopic pairs

^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}

and

^{41}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}

at magnetic fields up to

{10}^{3}\text{ }\mathrm{G}

. Positions and widths are determined combining a new measurement of the

^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}

^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}

atomic gas and for the production of ultracold polar molecules.

We perform extensive magnetic Feshbach spectroscopy of an ultracold mixture of fermionic

^{40}\mathrm{K}

and bosonic

^{87}\mathrm{Rb}

atoms. The magnetic-field locations of 13 interspecies resonances are used to construct a quantum collision model able to predict accurate collisional parameters for all $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. In particular, we determine the interspecies

s

-wave singlet and triplet scattering lengths for the $^{40}\mathrm{K}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ mixture as $(\ensuremath{-}108\ifmmode\pm\else\textpm\fi{}3){a}_{0}$ and $(\ensuremath{-}205\ifmmode\pm\else\textpm\fi{}5){a}_{0}$, respectively. We also predict accurate scattering lengths and the position of Feshbach resonances for the other $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ isotopic pairs. We discuss the consequences of our results for current and future experiments with ultracold $\mathrm{K}\text{\ensuremath{-}}\mathrm{Rb}$ mixtures.

We have investigated magnetically tunable Feshbach resonances in ultracold collisions of Rb with Yb in its metastable

{}^{3}{P}_{2}

and

{}^{3}{P}_{0}

states, using coupled-channel scattering and bound-state calculations. For the

{}^{3}{P}_{2}

state, we find sharp resonances when both atoms are in their lowest Zeeman sublevels. However, these resonances are decayed by inelastic processes that produce Yb atoms in

{}^{3}{P}_{1}

and

{}^{3}{P}_{0}

states. The molecules that might be produced by magnetoassociation at the

{}^{3}{P}_{2}

thresholds can decay by similar pathways and would have lifetimes no more than a few microseconds. For the

{}^{3}{P}_{0}

state, by contrast, there are resonances that are promising for magnetoassociation. There are resonances due to both rotating and nonrotating molecular states that are significantly stronger than the analogous resonances for

\mathrm{Yb}{(}^{1}S

). The ones due to rotating states are denser in magnetic field; in contrast to

\mathrm{Yb}{(}^{1}S

), they exist even for bosonic isotopes of

\mathrm{Yb}{(}^{3}{P}_{0}

{\mathrm{Rb}}_{2}

potentials obtained previously from the analysis of experiments on $^{87}\mathrm{Rb}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ collisions. We find resonances that occur at very low magnetic fields, below

10\phantom{\rule{0.3em}{0ex}}\mathrm{G}

, which may be useful for entanglement generation in optical lattices or atom chip magnetic traps.

Three magnetic-field induced heteronuclear Feshbach resonances were identified in collisions between bosonic

^{87}\mathrm{R}\mathrm{b}

and fermionic

^{40}\mathrm{K}

atoms in their absolute ground states. Strong inelastic loss from an optically trapped mixture was observed at the resonance positions of 492, 512, and $543\ifmmode\pm\else\textpm\fi{}2\text{ }\text{ }\mathrm{G}$. The magnetic-field locations of these resonances place a tight constraint on the triplet and singlet cross-species scattering lengths, yielding $(\ensuremath{-}281\ifmmode\pm\else\textpm\fi{}15){a}_{0}$ and $(\ensuremath{-}54\ifmmode\pm\else\textpm\fi{}12){a}_{0}$, respectively. The width of the loss feature at 543 G is $3.7\ifmmode\pm\else\textpm\fi{}1.5\text{ }\text{ }\mathrm{G}$ wide; this broad Feshbach resonance should enable experimental control of the interspecies interactions.

We have successfully prepared an optically trapped ultracold mixture of

{}^{23}

Na and

{}^{87}

Rb atoms and studied their interspecies Feshbach resonances. Using two different spin combinations, several

s

- and

p

-wave resonances are identified by observing high inelastic losses and temperature increases for both species near resonant magnetic field values. The two

s

-wave resonances observed below 500 G between atoms in their lowest-energy levels are possible candidates for Feshbach molecule association. Our results are well characterized by a coupled-channel model which also refines the ground-state interaction potentials between

{}^{23}

Na and

{}^{87}

Rb. This work opens up the prospect for preparing ultracold ensembles of ground-state bosonic NaRb molecules which are chemically stable and can provide strong dipolar interactions.