Aggregation of solutes in bosonic versus fermionic quantum fluids

Alexandra J Feinberg; Deepak Verma; Sean M O O'Connell-Lopez; Swetha Erukala; Rico Mayro P Tanyag; Weiwu Pang; Catherine A Saladrigas; Benjamin W Toulson; Mario Borgwardt; Niranjan Shivaram; Ming-Fu Lin; Andre Al Haddad; Wolfgang Jäger; Christoph Bostedt; Peter Walter; Oliver Gessner; Andrey F Vilesov

doi:10.1126/sciadv.abk2247

Aggregation of solutes in bosonic versus fermionic quantum fluids

Sci Adv. 2021 Dec 10;7(50):eabk2247. doi: 10.1126/sciadv.abk2247. Epub 2021 Dec 10.

Authors

Alexandra J Feinberg¹, Deepak Verma^{1

2}, Sean M O O'Connell-Lopez^{1

3}, Swetha Erukala¹, Rico Mayro P Tanyag^{1

4}, Weiwu Pang⁵, Catherine A Saladrigas^{6

7}, Benjamin W Toulson⁶, Mario Borgwardt⁶, Niranjan Shivaram^{8

9}, Ming-Fu Lin⁸, Andre Al Haddad¹⁰, Wolfgang Jäger¹¹, Christoph Bostedt^{10

12}, Peter Walter⁸, Oliver Gessner⁶, Andrey F Vilesov^{1

13}

Affiliations

¹ Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
² RA3, Intel Corporation, Ronler Acres, 2501 NE Century Blvd, Hillsboro, OR 97124, USA.
³ Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, 4600 Rickenbacker Cswy., Miami, FL 33149, USA.
⁴ Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark.
⁵ Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA.
⁶ Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁷ Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA.
⁸ SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.
⁹ Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, USA.
¹⁰ Laboratory for Femtochemistry (LSF), Paul Scherrer Institut, Forschungsstrasse 111, 5232 Villigen-PSI, Switzerland.
¹¹ Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.
¹² LUXS Laboratory for Ultrafast X-ray Sciences, Institute for Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
¹³ Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA.

Abstract

Quantum fluid droplets made of helium-3 (³He) or helium-4 (⁴He) isotopes have long been considered as ideal cryogenic nanolabs, enabling unique ultracold chemistry and spectroscopy applications. The droplets were believed to provide a homogeneous environment in which dopant atoms and molecules could move and react almost as in free space but at temperatures close to absolute zero. Here, we report ultrafast x-ray diffraction experiments on xenon-doped ³He and ⁴He nanodroplets, demonstrating that the unavoidable rotational excitation of isolated droplets leads to highly anisotropic and inhomogeneous interactions between the host matrix and enclosed dopants. Superfluid ⁴He droplets are laced with quantum vortices that trap the embedded particles, leading to the formation of filament-shaped clusters. In comparison, dopants in ³He droplets gather in diffuse, ring-shaped structures along the equator. The shapes of droplets carrying filaments or rings are direct evidence that rotational excitation is the root cause for the inhomogeneous dopant distributions.