We demonstrate that an interferometer based on modulated magnetic field pulses enables precise characterization of the energies and lifetimes of Efimov trimers irrespective of the magnitude and sign of the interactions in $^{85}\mathrm{Rb}$ thermal gases. Despite thermal effects, interference fringes develop when the dark time between the pulses is varied. This enables the selective excitation of coherent superpositions of trimer, dimer, and free-atom states. The interference patterns possess two distinct damping timescales at short and long dark times that are either equal to or twice as long as the lifetime of Efimov trimers, respectively. Specifically, this behavior at long dark times provides an interpretation of the unusually large damping timescales reported in a recent experiment with $^{7}\mathrm{Li}$ thermal gases [Yudkin et al., Phys. Rev. Lett. 122, 200402 (2019)]. Apart from that, our results constitute a stepping stone towards a high precision few-body state interferometry for dense quantum gases.We demonstrate that an interferometer based on modulated magnetic field pulses enables precise characterization of the energies and lifetimes of Efimov trimers irrespective of the magnitude and sign of the interactions in $^{85}\mathrm{Rb}$ thermal gases. Despite thermal effects, interference fringes develop when the dark time between the pulses is varied. This enables the selective excitation of coherent superpositions of trimer, dimer, and free-atom states. The interference patterns possess two distinct damping timescales at short and long dark times that are either equal to or twice as long as the lifetime of Efimov trimers, respectively. Specifically, this behavior at long dark times provides an interpretation of the unusually large damping timescales reported in a recent experiment with $^{7}\mathrm{Li}$ thermal gases [Yudkin et al., Phys. Rev. Lett. 122, 200402 (2019)]. Apart from that, our results constitute a stepping stone towards a high precision few-body state interferometry for dense quantum gases.

arXiv:2306.01199Physical Review ResearchNov 8, 20236 citations

Interferometry using magnetic sensitive states

Eduardo Gómez García

Apr 1, 20160 citations

Compensating three-dimensional field inhomogeneity in cold atom Efimov-state search by a time-averaged optical potential

Angang Liang, Y. Xie, Mingshan Huang +3 more

The Efimov effect and its universal property are of paramount importance in quantum few-body physics. Despite this, the predicted ground state Efimov resonance has not yet been observed in 39,40,41K-87Rb mixtures within the currently available observation window. Cooling atoms in the microgravity environment of outer space might overcome this limitation, whereas the residual curvature of the strong magnetic fields may result in significant atom leakage. In this work, we propose an optical method based on far-detuned time-averaged dipole potential to counteract the three-dimensional inhomogeneous field. The target intensity distribution can be conveniently obtained by modulating the central position of the quasi-1D print beam using acoustic optical modulators. Within a volume of 300 × 300 × 400 µm3, the residual potential fluctuations can be reduced by two orders of magnitude to less than 100 pK. The proposed approach offers a realistic prospect of investigating the Efimov-type resonance in the 40K-87Rb Bose-Fermi mixture.The Efimov effect and its universal property are of paramount importance in quantum few-body physics. Despite this, the predicted ground state Efimov resonance has not yet been observed in 39,40,41K-87Rb mixtures within the currently available observation window. Cooling atoms in the microgravity environment of outer space might overcome this limitation, whereas the residual curvature of the strong magnetic fields may result in significant atom leakage. In this work, we propose an optical method based on far-detuned time-averaged dipole potential to counteract the three-dimensional inhomogeneous field. The target intensity distribution can be conveniently obtained by modulating the central position of the quasi-1D print beam using acoustic optical modulators. Within a volume of 300 × 300 × 400 µm3, the residual potential fluctuations can be reduced by two orders of magnitude to less than 100 pK. The proposed approach offers a realistic prospect of investigating the Efimov-type resonance in the 40K-87Rb Bose-Fermi mixture.

Review of Scientific InstrumentsJul 1, 20232 citations

Finite-range corrections near a Feshbach resonance and their role in the Efimov effect

Paul Dyke, S. E. Pollack, Randall G. Hulet

We have measured the binding energy of ${}^{7}$ Li Feshbach molecules deep into the nonuniversal regime by associating atoms in a Bose-Einstein condensate with a modulated magnetic field. We extract the scattering length from these measurements, correcting for nonuniversal short-range effects using the field-dependent effective range. With this more precise determination of the Feshbach resonance parameters we reanalyze our previous data on the location of atom loss features produced by the Efimov effect [Pollack et al., Science 326, 1683 (2009)]. We find the measured locations of the three- and four-body Efimov features to be consistent with universal theory at the 20%--30% level.We have measured the binding energy of ${}^{7}$Li Feshbach molecules deep into the nonuniversal regime by associating atoms in a Bose-Einstein condensate with a modulated magnetic field. We extract the scattering length from these measurements, correcting for nonuniversal short-range effects using the field-dependent effective range. With this more precise determination of the Feshbach resonance parameters we reanalyze our previous data on the location of atom loss features produced by the Efimov effect [Pollack et al., Science 326, 1683 (2009)]. We find the measured locations of the three- and four-body Efimov features to be consistent with universal theory at the 20%--30% level.

arXiv:1302.0281Physical Review AAug 30, 201390 citations

^{85}\mathrm{Rb}

thermal gases. Despite thermal effects, interference fringes develop when the dark time between the pulses is varied. This enables the selective excitation of coherent superpositions of trimer, dimer, and free-atom states. The interference patterns possess two distinct damping timescales at short and long dark times that are either equal to or twice as long as the lifetime of Efimov trimers, respectively. Specifically, this behavior at long dark times provides an interpretation of the unusually large damping timescales reported in a recent experiment with

^{7}\mathrm{Li}

thermal gases [Yudkin et al., Phys. Rev. Lett. 122, 200402 (2019)]. Apart from that, our results constitute a stepping stone towards a high precision few-body state interferometry for dense quantum gases.

We have measured the binding energy of

{}^{7}

Li Feshbach molecules deep into the nonuniversal regime by associating atoms in a Bose-Einstein condensate with a modulated magnetic field. We extract the scattering length from these measurements, correcting for nonuniversal short-range effects using the field-dependent effective range. With this more precise determination of the Feshbach resonance parameters we reanalyze our previous data on the location of atom loss features produced by the Efimov effect [Pollack et al., Science 326, 1683 (2009)]. We find the measured locations of the three- and four-body Efimov features to be consistent with universal theory at the 20%--30% level.