Cold atom guidance in a capillary using blue-detuned, hollow optical modes

Area of Science:

• Atomic physics
• Quantum optics
• Nanophotonics

Background:

• Atom guiding in optical waveguides is crucial for quantum technologies.
• Hollow core dielectric waveguides offer unique confinement properties.
• Different light modes within waveguides interact distinctively with atoms.

Purpose of the Study:

• To demonstrate guiding of cold 85Rb atoms using various cylindrical hollow modes in a dielectric waveguide.
• To compare atom guiding efficiency and scattering rates between different blue-detuned and red-detuned modes.
• To investigate the potential of higher-order hollow modes for reduced atom-light interaction.

Main Methods:

• Guiding cold 85Rb atoms through a 100-micron-diameter hollow core dielectric waveguide.
• Utilizing blue-detuned light in 1st and 2nd order hollow modes (TE01, HE31, EH11, HE12).
• Comparing results with guidance in the red-detuned fundamental HE11 mode.
• Measuring atom scattering rates by observing recoil effects.

Main Results:

• Atoms were successfully transported using blue-detuned 1st and 2nd order hollow modes.
• Higher atom numbers were guided using the red-detuned HE11 mode.
• A 10-fold reduction in scattering rate was observed with 2nd order modes (r4 intensity profile).
• Blue-detuned modes confined atoms to low-intensity regions, away from waveguide walls.

Conclusions:

• Second-order hollow modes significantly reduce atom scattering rates compared to the fundamental HE11 mode.
• Blue-detuned modes offer reduced atom perturbation by confining atoms to low-intensity regions.
• A hybrid approach using red-detuned guides to load atoms into blue-detuned modes enables high atom numbers with low perturbation.