Dipolar Quantum Mixtures of Erbium and Dysprosium Atoms

Featured in Physics
Editors' Suggestion

Dipolar Quantum Mixtures of Erbium and Dysprosium Atoms

A. Trautmann, P. Ilzhöfer, G. Durastante, C. Politi, M. Sohmen, M. J. Mark, and F. Ferlaino

Phys. Rev. Lett. 121, 213601 – Published 21 November 2018

See Synopsis: Making Mixtures of Magnetic Condensates

Abstract

We report on the first realization of heteronuclear dipolar quantum mixtures of highly magnetic erbium and dysprosium atoms. With a versatile experimental setup, we demonstrate binary Bose-Einstein condensation in five different Er-Dy isotope combinations, as well as one Er-Dy Bose-Fermi mixture. Finally, we present first studies of the interspecies interaction between the two species for one mixture.

Received 20 July 2018
Revised 8 October 2018

DOI:https://doi.org/10.1103/PhysRevLett.121.213601

Physics Subject Headings (PhySH)

Bose gases Bose-Einstein condensates Cold atoms & matter waves Cooling & trapping Dipolar gases Fermi gases Long-range interactions Mixtures of atomic and/or molecular quantum gases

Atomic, Molecular & OpticalCondensed Matter, Materials & Applied Physics

Synopsis

Making Mixtures of Magnetic Condensates

Published 21 November 2018

A condensate mixing two species of strongly magnetic atoms provides a new experimental window into many-body phenomena.

See more in Physics

Authors & Affiliations

A. Trautmann^1,*, P. Ilzhöfer^1,2,*, G. Durastante^1,2, C. Politi¹, M. Sohmen^1,2, M. J. Mark^1,2, and F. Ferlaino^1,2

¹Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
²Institut für Experimentalphysik und Zentrum für Quantenoptik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria

^*These authors contributed equally to this work.

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 121, Iss. 21 — 23 November 2018

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Images

Figure 1
Binary Bose-Einstein condensation in a ${}^{166}{Er} − {}^{164}{Dy}$ mixture. (a)–(c) Pairs of TOF absorption images at different evaporation stages, showing (a) a thermal mixture at about 180 nK, (b) an Er cloud at the onset of condensation coexisting with a thermal Dy gas at about 80 nK, and (c) the binary dipolar BEC with total atom numbers $N = 3.4 \times 10^{4} (2.6 \times 10^{4})$ for Er(Dy) with condensate fractions of about 45%. $\tilde{x}$ denotes the horizontal axis perpendicular to the imaging axis. (d),(e) Density profiles integrated along $z$ , extracted from (c). Solid lines depict the 1D bimodal fit, the dotted lines show Gaussian fits to the thermal components. (f)–(h) BECs with a controlled number imbalance giving about $N^{Er} = (3.2, 6.4, 9.2) \times 10^{4}$ with (35, 70, 85)% condensate fraction and $N^{Dy} = (3.1, 2.9, 0.9) \times 10^{4}$ with (30, 55, 30)% condensate fraction for (f)–(h), respectively. The deformations and the relative displacement of the clouds are caused by interspecies interaction (see main text). The color bar indicates the optical density.
Reuse & Permissions
Figure 2
(a) Evaporation trajectories: $PSD / {PSD}_{0}$ as a function of $N / N_{0}$ . Filled squares (circles) indicate the Er(Dy) trajectory in mixture operation. The lines are linear fits to the data for evaporation in the single-beam (ii) and crossed-beam (iii) ODT (see main text). Open symbols show the single-species operation for Er (squares) and for Dy with small (circles) and large (diamonds) initial atom numbers. In the latter case, Dy condenses alone. (b) Atom numbers in the mixture of Er (red) and Dy (blue) at the onset of condensation as a function of the magnetic-field value during evaporation. Condensation is reached for atom numbers above about $3.5 \times 10^{4}$ (gray region). We record the best performance for a ddBEC around 2.075 G. Arrows indicate the position of known single-species Feshbach resonances [57, 58, 59].
Reuse & Permissions
Figure 3
Absorption pictures of the double-degenerate Bose-Bose mixtures (a)–(d) and the Bose-Fermi mixture (e). The pictures are averaged over 5–10 single shots. For all combinations, degeneracy is reached with the evaporation ramp optimized for the ${}^{166}{Er} − {}^{164}{Dy}$ mixture (cf. Fig. 1). $B_{evap}$ is listed in Table 1. Typical condensate fractions are around 30%, total atom numbers range between $1 \times 10^{4}$ and $3.5 \times 10^{4}$ atoms. For the imbalanced case, higher condensate fractions can be achieved (see Fig. 1). For the ${}^{161}{Dy}$ Fermi gas, $N = 8 \times 10^{3}$ , $T / T_{F} \approx 0.5$ , and $TOF = 15 ms$ .
Reuse & Permissions
Figure 4
Evidence of interspecies interactions in the ${}^{166}{Er} − {}^{164}{Dy}$ mixture: absorption pictures of Er and Dy in mixture (a) and single-species (b),(c) operation. (d),(e) Filled symbols show the c.m. position along $z$ of the Dy BEC (d) and the Er BEC (e) after removal of the other species with resonant light. The gray region indicates the transient time until full removal. The solid lines are damped sine fits to the oscillations. For comparison, open symbols show the c.m. position in a thermal mixture.
Reuse & Permissions

Physical Review Letters