Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review Research

Imprinting knots in a spinor Bose-Einstein condensate via a Raman process without knotted optical fields

Zekai Chen, Elisha Haber, N. P. Bigelow

Published Nov 15, 2022• 1 citation
Publisher

Abstract

We propose a dynamical imprinting scheme to create nodal lines of torus and lemniscate knots via a Raman process in a dilute spinor Bose-Einstein condensate. We calculate the desired parameters and the necessary spatial profiles of the Raman laser fields that couple a realistic multilevel atomic system, and demonstrate the imprinting results via a numerical calculation. Additionally, we show the capability of our method to adjust the size and the aspect ratio of the knotted nodal lines by tuning the parameters of Raman lasers that propagate along different directions.

DOI
10.1103/physrevresearch.4.043109

Related papers

Phase imprinting of vortices in Bose-Einstein condensates using shaped light

Jasper Smits

Vorticity in superfluids has been studied for decades. In atomic BECs, vorticity was induced by stirring with laser beams. In this thesis, phase imprinting is introduced as an alternative method to induce vorticity in a BEC. By using a Liquid Crystal-on-Silicon spatial light modulator the phase of a laser beam can be shaped into any spatial profile, limited only by the imaging resolution. By using this shaped light in a two-photon Raman transfer, the phase of the electromagnetic field is transferred on to the Bose-condensed atoms.\n\nSimulations are performed for light containing a single phase winding, taking into account that the vortex in this beam has a finite vortex core size due to limited imaging resolution. It follows that the finite core size has an incomplete transfer as a result, but the phase winding is imprinted on to the atoms transferred to the second component.\n\nAlso, experimentally the two-photon Raman transition which is needed has been realised. However, the transfer process is impeded by a different two-photon process occuring at the same time, and by superradiant Rayleigh scattering. Recommendations are given to suppress these effects and successfully imprint the phase from the shaped light on to the atoms.

•Jan 1, 2016•0 citations

Raman fingerprints on the Bloch sphere of a spinor Bose–Einstein condensate

Justin T. Schultz, Azure Hansen, Joseph D. Murphree +2 more

We explore the geometric interpretation of a diabatic, two-photon Raman process as a rotation on the Bloch sphere for a pseudo-spin-1/2 system. The spin state of a spin-1/2 quantum system can be described by a point on the surface of the Bloch sphere, and its evolution during a Raman pulse is a trajectory on the sphere determined by properties of the optical beams: the pulse area, the relative intensities and phases and the relative frequencies. We experimentally demonstrate key features of this model with a 87Rb spinor Bose–Einstein condensate, which allows us to examine spatially dependent signatures of the Raman beams. The two-photon detuning allows us to precisely control the spin density and imprinted relative phase profiles, as we show with a coreless vortex. With this comprehensive understanding and intuitive geometric interpretation, we use the Raman process to create and tailor as well as study and characterize exotic topological spin textures in spinor BECs.

arXiv:1601.00327•Journal of Modern Optics•Feb 1, 2016•9 citations

Excitation of knotted vortex lines in matter waves

Fabian Maucher, S. A. Gardiner, Ifan G. Hughes

We study the creation of knotted ultracold matter waves in Bose–Einstein condensates via coherent two-photon Raman transitions with a Λ level configuration. The Raman transition allows an indirect transfer of atoms from the internal state to the target state via an excited state , that would be otherwise dipole-forbidden. This setup enables us to imprint three-dimensional knotted vortex lines embedded in the probe field to the density in the target state. We elaborate on experimental feasibility as well as on subsequent dynamics of the matter wave.

arXiv:1512.01012•New Journal of Physics•Jun 13, 2016•24 citations

Raman coupling of Zeeman sublevels in an alkali-metal Bose-Einstein condensate

Kevin Wright, L. Suzanne Leslie, N. P. Bigelow

We investigate amplitude and phase control of the components of the spinor order parameter of a $^{87}\mathrm{Rb}$ Bose-Einstein condensate. By modeling the interaction of the multilevel atomic system with a pair of Raman-detuned laser pulses, we show that it is possible to construct a pulse-sequence protocol for producing a desired state change within a single Zeeman manifold. We present several successful elementary tests of this protocol in both the $F=1$ and $F=2$ Zeeman manifolds of $^{87}\mathrm{Rb}$ using the ${D}_{1}$ transitions. We describe specific features of the interaction, which are important for multimode, spatially varying field configurations, including the role of state-dependent, light-induced potentials.

arXiv:0808.1703•Physical Review A•Nov 17, 2008•27 citations

Topological atom optics and beyond with knotted quantum wavefunctions

Maitreyi Jayaseelan, Joseph D. Murphree, Justin T. Schultz +2 more

Abstract Atom optics demonstrates optical phenomena with coherent matter waves, providing a foundational connection between light and matter. Significant advances in optics have followed the realization of structured light fields hosting complex singularities and topologically non-trivial characteristics. However, analogous studies are still in their infancy in the field of atom optics. Here, we investigate and experimentally create knotted quantum wavefunctions in spinor Bose–Einstein condensates which display non-trivial topologies. In our work we construct coordinated orbital and spin rotations of the atomic wavefunction, engineering a variety of discrete symmetries in the combined spin and orbital degrees of freedom. The structured wavefunctions that we create map to the surface of a torus to form torus knots, Möbius strips, and a twice-linked Solomon’s knot. In this paper we demonstrate close connections between the symmetries and underlying topologies of multicomponent atomic systems and of vector optical fields—a realization of topological atom-optics.

arXiv:2312.09619•Communications Physics•Jan 4, 2024•6 citations

Engineering vortex rings and systems for controlled studies of vortex interactions in Bose-Einstein condensates

Janne Ruostekoski, Zachary Dutton

We study controlled methods of preparing vortex configurations in atomic Bose-Einstein condensates and their use in the studies of fundamental vortex scattering, reconnection processes, and superfluid sound emission. We explore techniques of imprinting vortex rings by means of coherently driving internal atomic transitions with electromagnetic fields which exhibit singular phase profiles. In particular, we show that a vortex ring can be prepared by two focused co-propagating Gaussian laser beams. More complex vortex systems may also be imprinted by directly superposing simpler field configurations or by programming their phase profiles on optical holograms. We analyze specific examples of two merging vortex rings in a trapped two-species $^{87}\mathrm{Rb}$ gas. We calculate the radiated sound energy in the reconnection process and show that the vortex relaxation and the redistribution of sound energy can be controlled by the imprinting process. As another creation technique, we study engineering pairs of two-dimensional point vortices in the condensates using a `light roadblock' in ultraslow light propagation. We show how this can be used to study vortex collisions in compressible superfluids and how these collisions result in energy dissipation via phonons and, sometimes, annihilation of vortex pairs.

arXiv:cond-mat/0507032•Physical Review A•Dec 30, 2005•68 citations
We propose a dynamical imprinting scheme to create nodal lines of torus and lemniscate knots via a Raman process in a dilute spinor Bose-Einstein condensate. We calculate the desired parameters and the necessary spatial profiles of the Raman laser fields that couple a realistic multilevel atomic system, and demonstrate the imprinting results via a numerical calculation. Additionally, we show the capability of our method to adjust the size and the aspect ratio of the knotted nodal lines by tuning the parameters of Raman lasers that propagate along different directions.
Vorticity in superfluids has been studied for decades. In atomic BECs, vorticity was induced by stirring with laser beams. In this thesis, phase imprinting is introduced as an alternative method to induce vorticity in a BEC. By using a Liquid Crystal-on-Silicon spatial light modulator the phase of a laser beam can be shaped into any spatial profile, limited only by the imaging resolution. By using this shaped light in a two-photon Raman transfer, the phase of the electromagnetic field is transferred on to the Bose-condensed atoms.\n\nSimulations are performed for light containing a single phase winding, taking into account that the vortex in this beam has a finite vortex core size due to limited imaging resolution. It follows that the finite core size has an incomplete transfer as a result, but the phase winding is imprinted on to the atoms transferred to the second component.\n\nAlso, experimentally the two-photon Raman transition which is needed has been realised. However, the transfer process is impeded by a different two-photon process occuring at the same time, and by superradiant Rayleigh scattering. Recommendations are given to suppress these effects and successfully imprint the phase from the shaped light on to the atoms.
We explore the geometric interpretation of a diabatic, two-photon Raman process as a rotation on the Bloch sphere for a pseudo-spin-1/2 system. The spin state of a spin-1/2 quantum system can be described by a point on the surface of the Bloch sphere, and its evolution during a Raman pulse is a trajectory on the sphere determined by properties of the optical beams: the pulse area, the relative intensities and phases and the relative frequencies. We experimentally demonstrate key features of this model with a 87Rb spinor Bose–Einstein condensate, which allows us to examine spatially dependent signatures of the Raman beams. The two-photon detuning allows us to precisely control the spin density and imprinted relative phase profiles, as we show with a coreless vortex. With this comprehensive understanding and intuitive geometric interpretation, we use the Raman process to create and tailor as well as study and characterize exotic topological spin textures in spinor BECs.
We study the creation of knotted ultracold matter waves in Bose–Einstein condensates via coherent two-photon Raman transitions with a Λ level configuration. The Raman transition allows an indirect transfer of atoms from the internal state to the target state via an excited state , that would be otherwise dipole-forbidden. This setup enables us to imprint three-dimensional knotted vortex lines embedded in the probe field to the density in the target state. We elaborate on experimental feasibility as well as on subsequent dynamics of the matter wave.
We investigate amplitude and phase control of the components of the spinor order parameter of a 87Rb^{87}\mathrm{Rb}87Rb Bose-Einstein condensate. By modeling the interaction of the multilevel atomic system with a pair of Raman-detuned laser pulses, we show that it is possible to construct a pulse-sequence protocol for producing a desired state change within a single Zeeman manifold. We present several successful elementary tests of this protocol in both the F=1F=1F=1 and F=2F=2F=2 Zeeman manifolds of 87Rb^{87}\mathrm{Rb}87Rb using the D1{D}_{1}D1​ transitions. We describe specific features of the interaction, which are important for multimode, spatially varying field configurations, including the role of state-dependent, light-induced potentials.
Abstract Atom optics demonstrates optical phenomena with coherent matter waves, providing a foundational connection between light and matter. Significant advances in optics have followed the realization of structured light fields hosting complex singularities and topologically non-trivial characteristics. However, analogous studies are still in their infancy in the field of atom optics. Here, we investigate and experimentally create knotted quantum wavefunctions in spinor Bose–Einstein condensates which display non-trivial topologies. In our work we construct coordinated orbital and spin rotations of the atomic wavefunction, engineering a variety of discrete symmetries in the combined spin and orbital degrees of freedom. The structured wavefunctions that we create map to the surface of a torus to form torus knots, Möbius strips, and a twice-linked Solomon’s knot. In this paper we demonstrate close connections between the symmetries and underlying topologies of multicomponent atomic systems and of vector optical fields—a realization of topological atom-optics.
We study controlled methods of preparing vortex configurations in atomic Bose-Einstein condensates and their use in the studies of fundamental vortex scattering, reconnection processes, and superfluid sound emission. We explore techniques of imprinting vortex rings by means of coherently driving internal atomic transitions with electromagnetic fields which exhibit singular phase profiles. In particular, we show that a vortex ring can be prepared by two focused co-propagating Gaussian laser beams. More complex vortex systems may also be imprinted by directly superposing simpler field configurations or by programming their phase profiles on optical holograms. We analyze specific examples of two merging vortex rings in a trapped two-species 87Rb^{87}\mathrm{Rb}87Rb gas. We calculate the radiated sound energy in the reconnection process and show that the vortex relaxation and the redistribution of sound energy can be controlled by the imprinting process. As another creation technique, we study engineering pairs of two-dimensional point vortices in the condensates using a `light roadblock' in ultraslow light propagation. We show how this can be used to study vortex collisions in compressible superfluids and how these collisions result in energy dissipation via phonons and, sometimes, annihilation of vortex pairs.