Surface-plasmon based dispersive detection and spectroscopy of ultracold atoms

Abstract

The paper reports on the optical detection and spectroscopy of ultracold atoms near a gold surface. A probe light field is used to excite surface plasmon polaritons. The refractive index of the atomic gas shifts the plasmon resonance and changes the reflected light power. Thus, the sensitivity of the detection is plasmonically enhanced. Absorption of photons from the evanescent wave is avoided by detuning the laser from atomic resonance which makes the detection scheme potentially nondestructive. The spectrum of the signal is determined by a Fano resonance. We show that atoms can be detected nondestructively with single atom resolution for typical parameters in cold atom experiments. Thus, the method is suitable for quantum nondemolition measurements of matter wave amplitudes. Experimentally, we measure a technically-limited sensitivity of 30 atoms and extend the detection scheme to dispersively image the atom cloud near the surface.

8 pages, 4 figures

References in corpus (5)

• Two-dimensional Bose-Einstein condensate in an optical surface trap
• Improved detection of small atom numbers through image processing
• Fano resonances and fluorescence enhancement of a dipole emitter near a plasmonic nanoshell
• Observation of modified radiative properties of cold atoms in vacuum near a dielectric surface
• Controlling photon bunching and antibunching of two quantum emitters near a core-shell sphere

Cited by in corpus (2)

• A perspective on integrated atomo-photonic waveguide circuits
• Spoof Surface Waves on Non Conducting Structured Interfaces