Nonlinear quantum optics for spinor slow light

TL;DR

This paper explores quantum nonlinear effects in a double tripod atom-light scheme, enabling control of spinor slow light and photon interactions, with potential for advanced quantum information applications.

Contribution

It introduces a novel double tripod scheme that combines spin-orbit coupling with photon interactions, allowing new control over spinor slow light and photon behavior.

Findings

Photon interactions can be repulsive or attractive depending on detuning signs.

The scheme enables generation of a second probe beam at zero two-photon detuning.

It demonstrates control over light quanta using atomic Rydberg states.

Abstract

We investigate quantum nonlinear effects at a level of individual quanta in a double tripod atom-light coupling scheme involving two atomic Rydberg states. In such a scheme the slow light coherently coupled to strongly interacting Rydberg states represents a two-component or spinor light. The scheme provides additional possibilities for the control and manipulation of light quanta. A distinctive feature of the proposed setup is that it combines the spin-orbit coupling for the spinor slow light with an interaction between the photons, enabling generation of the second probe beam even when two-photon detuning is zero. Furthermore, the interaction between the photons can become repulsive if the one-photon detunings have opposite signs. This is different from a single ladder atom-light coupling scheme, in which the interaction between the photons is attractive for both positive and negative detunings, as long as the Rabi frequency of the control beam is not too large.