US-20260128189-A1 - TRAPPING OF SINGLE ULTRACOLD ATOMS AND MOLECULES IN METASURFACE OPTICAL TWEEZER ARRAYS

Abstract

The disclosed subject matter relates to systems and methods for trapping single atoms and molecules using metasurface-generated optical tweezer arrays. A metasurface, comprising a plurality of subwavelength-spaced pixels fabricated from dielectric materials, is configured to generate an optical tweezer array from an incident laser beam in which particles are trapped. The metasurface enables the creation of highly uniform and scalable tweezer arrays with arbitrary geometries, dimensionalities, and trap spacings, supporting array sizes exceeding 10,000 traps. The compact, robust design and high power-handling capabilities of the metasurface facilitate direct trapping of ultracold particles, such as strontium atoms, with a vacuum chamber, and allow for field-deployable quantum devices. The disclosed approach achieves high uniformity in trap intensity and position, enabling advanced quantum applications.

Inventors

• Sebastian Will
• Nanfang Yu
• Aaron Holman
• Yuan Xu
• Ximo Sun
• Jiahao Wu
• Bojeong SEO

Assignees

• THE TRUSTEES OF COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK

Dates

Publication Date

20260507

Application Date

20251107

Claims (20)

1. 1 . A system for trapping ultracold particles therein using an incident laser beam, comprising: a metasurface comprising a plurality of subwavelength-spaced pixels configured to imprint a phase profile on the incident laser beam; wherein the metasurface is configured to generate an optical tweezer array from the incident laser beam; wherein the metasurface is fabricated from one or more dielectric materials; and wherein the optical tweezer array comprises a plurality of traps.
2. 2 . The system of claim 1 , wherein the metasurface is configured to generate and focus the optical tweezer array.
3. 3 . The system of claim 1 , wherein the metasurface is configured to generate the optical tweezer array in conjunction with focusing optics.
4. 4 . The system of claim 1 , further comprising a vacuum chamber.
5. 5 . The system of claim 4 , wherein the metasurface is located at a position selected from the group consisting of inside the vacuum chamber and outside the vacuum chamber.
6. 6 . The system of claim 4 , further comprising relay optics, wherein the relay optics are positioned between the metasurface and the particles.
7. 7 . The system of claim 1 , wherein the optical tweezer array is composed of an arbitrary geometry and an arbitrary dimensionality.
8. 8 . The system of claim 7 , wherein the arbitrary dimensionality is selected from the group consisting of one-dimension, two-dimension, and three-dimension.
9. 9 . The system of claim 1 , wherein the one or more dielectric materials have high refractive indexes.
10. 10 . The system of claim 2 , wherein the metasurface has a numerical aperture greater than 0.3.
11. 11 . The system of claim 1 , wherein the pixels have a cross-sectional size of approximately 5% to 100% of the wavelength of the incident laser beam and a height of approximately 10% to 300% of the wavelength of the incident laser beam.
12. 12 . The system of claim 1 , wherein the incident laser beam has a wavelength from 100 to 10000 nanometers.
13. 13 . The system of claim 1 , wherein the plurality of traps is configured to trap ultracold particles.
14. 14 . The system of claim 13 , wherein the ultracold particles are strontium atoms.
15. 15 . The system of claim 1 , wherein the plurality of traps has intensity uniformity greater than 90%.
16. 16 . The system of claim 1 , wherein the plurality of traps comprises at least 10,000 traps.
17. 17 . A method for trapping single particles, comprising: directing a laser beam onto a metasurface comprising subwavelength pixels; modulating the phase of the laser beam using the metasurface, wherein the metasurface is configured to generate an optical tweezer array; and trapping particles in the optical tweezer array.
18. 18 . The method of claim 17 , wherein the metasurface is configured to generate and focus the optical tweezer array.
19. 19 . The method of claim 17 , wherein the metasurface is configured to generate the optical tweezer array in conjunction with focusing optics.
20. 20 . The method of claim 17 , further comprising detecting trapped particles by fluorescence imaging using a high-numerical-aperture lens and a camera.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This Non-Provisional application claims priority to the U.S. Provisional Application Ser. No. 63/717,627, filed on Nov. 7, 2024, the contents of which are hereby incorporated by reference in its entirety. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH This invention was made with government support under 1936359, 2040702 and 2004685 awarded by the National Science Foundation and under FA95500-16-1-0322 and FA9550-23-1-0404 awarded by the Air Force Office of Scientific Research. The government has certain rights in the invention. BACKGROUND The disclosed subject matter relates to optical tweezer arrays for use in quantum applications. Optical tweezer arrays can control ultracold particles in quantum applications, including quantum computing, simulation, and metrology. Applications include quantum spin systems, high-fidelity Rydberg quantum gates, error-corrected quantum computation, optical tweezer clocks, and cavity quantum electrodynamics and correlated atom-photon interactions. The ability to generate high-quality optical tweezer arrays is required for certain use cases. A tweezer array can include numerous tightly focused laser beams, each constituting a trap for a single particle. Important criteria for the platform can include trap uniformity and scalability. Certain optical tweezer arrays are generated via active beam-shaping devices, such as acousto-optical deflectors (AODs), liquid crystal-spatial light modulators (SLMs), or digital micromirror devices (DMDs). These devices can require complex control electronics and projection optics with high numerical apertures (NA) to relay the tweezer arrays onto ultracold particles. The NA measures the angular range within which an optical system can focus or collect light. Technical complexity and limitations can constrain array sizes to ˜10,000 traps, which can limit the quantum applications that can be pursued. Certain alternative techniques, such as amplitude masks and microlens arrays, have limited beam-shaping capabilities and present challenges to achieving highly uniform arrays. Holographic metasurfaces can be used to generate versatile and scalable tweezer arrays. Metasurfaces can be flat optical devices comprised of pixels and can imprint an arbitrary phase mask onto an incident laser beam-generating and focusing an optical tweezer array. Metasurfaces can provide high power-handling capabilities, diffraction-limited focusing, and polarization control. There exists a need for improved optical tweezer arrays. SUMMARY The disclosed subject matter provides techniques for trapping ultracold particles using an incident laser beam. An example system can include a metasurface with multiple subwavelength-spaced pixels which can imprint a phase profile on the incident laser beam. The metasurface can generate an optical tweezer array from the incident laser beam. The metasurface can be fabricated from dielectric materials. The optical tweezer array can include multiple traps. In certain embodiments, the metasurface can generate and focus the optical tweezer array. In certain embodiments, the metasurface can generate the optical tweezer array in conjunction with focusing optics. In certain embodiments, the system can include a vacuum chamber. In additional embodiments, the metasurface can be either located inside or outside the vacuum chamber. In additional embodiments, the system can include relay optics which can be located between the metasurface and the particles. In certain embodiments, the optical tweezer array has an arbitrary geometry and an arbitrary dimensionality. In certain embodiments, the optical tweezer array can be one-dimensional, two-dimensional, or three-dimensional. In certain embodiments, the dielectric materials can have high refractive indexes. In certain embodiments, the metasurface can have a numerical aperture greater than 0.3. In certain embodiments, the pixels can have a cross-sectional cell size of approximately 5% to 100% of the wavelength of the incident laser beam, and a height of approximately 10% to 300% of the wavelength of the incident laser beam. In certain embodiments, the incident laser beam can have a wavelength ranging from 100 to 10000 nanometers. In certain embodiments, the plurality of traps can trap ultracold particles. In certain embodiments, the ultracold particles can be strontium atoms. In certain embodiments, the traps can have intensity uniformity greater than 90%. In certain embodiments, the plurality of traps can have over 10,000 traps. The disclosed subject matter also provides methods for trapping single particles. An example method can include directing a laser beam onto a metasurface with subwavelength pixels, modulating the phase of the laser beam using the metasurface, which can generate an optical tweezer array, and trapping particles in the optical tweezer array. In certain embodiments, the metasurface can generate and focus the optical tweezer array. In certai