Rapidity and momentum distributions of one-dimensional dipolar quantum gases

Editors' Suggestion
Letter

Rapidity and momentum distributions of one-dimensional dipolar quantum gases

Kuan-Yu Li, Yicheng Zhang, Kangning Yang, Kuan-Yu Lin, Sarang Gopalakrishnan, Marcos Rigol, and Benjamin L. Lev

Phys. Rev. A 107, L061302 – Published 8 June 2023

Abstract

We explore the effect of tunable integrability-breaking dipole-dipole interactions in the equilibrium states of highly magnetic one-dimensional (1D) Bose gases of dysprosium at low temperatures. We experimentally observe that in the strongly correlated Tonks-Girardeau regime, rapidity and momentum distributions are nearly unaffected by the dipolar interactions. By contrast, we also observe that significant changes of these distributions occur when decreasing the strength of the contact interactions. We show that the main experimental observations are captured by modeling the system as an array of 1D gases with only contact interactions, dressed by the contribution of the short-range part of the dipolar interactions. Improvements to theory-experiment correspondence will require different tools tailored to near-integrable models possessing both short- and long-range interactions.

Received 17 November 2022
Revised 29 January 2023
Accepted 22 May 2023

DOI:https://doi.org/10.1103/PhysRevA.107.L061302

Physics Subject Headings (PhySH)

Bose gases Ultracold collisions

1-dimensional systems

Exact solutions for many-body systems Many-body techniques

Atomic, Molecular & OpticalCondensed Matter, Materials & Applied Physics

Authors & Affiliations

Kuan-Yu Li^1,2,*, Yicheng Zhang^3,4,5,*, Kangning Yang^2,6, Kuan-Yu Lin^2,6, Sarang Gopalakrishnan^3,7, Marcos Rigol ³, and Benjamin L. Lev ^1,2,6

¹Department of Applied Physics, Stanford University, Stanford, California 94305, USA
²E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
³Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
⁴Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, Norman, Oklahoma 73019, USA
⁵Center for Quantum Research and Technology, The University of Oklahoma, Norman, Oklahoma 73019, USA
⁶Department of Physics, Stanford University, Stanford, California 94305, USA
⁷Department of Electrical and Computer Engineering, Princeton University, Princeton, New Jersey 08544, USA

^*These authors contributed equally to this work.

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 107, Iss. 6 — June 2023

Reuse & Permissions

Access Options

Article Available via CHORUS

Download Accepted Manuscript

Author publication services for translation and copyediting assistance advertisement

Images

Figure 1
(a) Schematic illustrating the experimental sequence for measuring the rapidity distribution of a dipolar 1D gas. A dipolar 1D gas is prepared with a magnetic field magnitude $B$ and angle $θ_{B}$ resulting in contact strength $g_{1D}$ . Then, the underlying harmonic trap is suddenly removed, while the transverse confinement is maintained. This allows the quantum gas to expand in a flat, 1D trap along $\hat{x}$ . Time-of-flight absorption imaging follows 3D expansion by switching off all optical traps. The blue arrows denote the rapidities. (b) Timing sequence for creating a dipolar 1D gas at dipolar angle $θ_{B}$ and $g_{1D}$ . Once the quantum gas is loaded into a quasi-1D trap, the $B$ -field angle is slowly rotated from $55^{\circ}$ to $θ_{B} = 0^{\circ}, 35^{\circ}$ , or $90^{\circ}$ in a time $t_{θ_{B}}$ , or kept at $55^{\circ}$ , as the experiment requires. $g_{1D}$ is then set to its final value by ramping the $B$ -field strength near a Feshbach resonance in a time $t_{γ} = 50$ ms.
Reuse & Permissions
Figure 2
The TOF density distribution for $θ_{B} = 55^{\circ}$ and $γ_{T} \approx 16$ for $t_{1D} = 0$ –20 ms. The width of the distributions' $θ$ has been scaled by $ℏ k_{R}$ . Data at times $> 15$ ms suffer from imaging artifacts and are not used. Inset: The evolution of the FWHM of the distribution vs $t_{1D}$ for $γ_{T} \approx 16$ at $θ_{B} = 55^{\circ}$ (light green) and $γ_{T} \approx 19$ at $θ_{B} = 90^{\circ}$ (red). Error bars are explained in Ref. [8].
Reuse & Permissions
Figure 3
Momentum and rapidity distributions; $θ$ denotes either momentum or rapidity. Solid lines show the experimental momentum (blue) and rapidity (red) distributions, while the dashed lines show the simulation results. (a) Distributions for $θ_{B} = 90^{\circ}$ and $γ_{T} \approx 420$ in the TG limit. The simulations use $T^{*} = 15$ nK and $U_{2D}^{*} = 5 E_{R}$ . (b) Distributions for $θ_{B} = 55^{\circ}$ and $γ_{T} \approx 6.7$ . Simulations use $T^{*} = 25$ nK and $U_{2D}^{*} = 5 E_{R}$ . Insets show the theoretical error used to select $T^{*}$ [8].
Reuse & Permissions
Figure 4
(a) Measured momentum and rapidity distributions at field angles $θ_{B} = 0^{\circ}$ (red), $35^{\circ}$ (orange), $55^{\circ}$ (green), and $90^{\circ}$ (blue) with $γ_{T} (θ_{B} = 55^{\circ}) \approx 3.2$ , 6.7, and 16. $θ$ denotes either momentum or rapidity. (b) Corresponding simulation curves. The insets in (a) show the total (interaction plus kinetic) energy that has been experimentally estimated from the rapidity distributions. Insets in (b) show the theoretically estimated total DDI energies, intertube plus short-range intratube. The $θ_{B}$ dependence comes from the contribution to $g_{1D}$ from the short-range part of the intratube 1D DDI. Note that the theory curves are missing for the case of $γ_{T} (55^{\circ}) \approx 3.2$ and $θ_{B} = 0^{\circ}$ because $g_{1D}$ becomes negative and we cannot simulate that regime.
Reuse & Permissions

Physical Review A

covering atomic, molecular, and optical physics and quantum science