A Coherent One-Dimensional Atom

Strong-light matter interaction provides effective approach to modifying photon statistics and forming exotic quantum states of photons. The prerequisite is a very efficient coupling between photons and a single quantum emitter with highly coherent optical transitions. While coherent optical transitions for pristine systems such as atoms is trivially achievable, such a performance is a rarity for solid-state quantum emitters due to the interaction between the emitter and its surrounding environment. In his contribution, we demonstrate a strong nonlinearity using an indium arsenide quantum dot, a solid-state artificial atom [1]. We achieve a strong extinction of a laser field by 99.2% due to interaction with the quantum dot. Our experiment involves a one-sided microcavity and a single quantum dot. The cavity exhibits a Q-factor of ~13000 and a Purcell factor of ~15. Details of the cavity design and its characterization are reported earlier [2,3]. The transmission on resonance with this dipole shows a strong nonlinearity; while the extinction is near complete for the low incident laser power (<0.1 nW), at higher powers, the transmission is recovered. The quantum nature of the nonlinearity manifests itself clearly in the statistics of photons as well. The autocorrelation measurements on the transmitted light also show a strong bunching behavior by a record factor of 582 compared to a laser field, which to our knowledge, is the strongest bunching of photons reported to date. The observed photon-number discriminating interaction enables photon-photon interactions at the single-photon limit and may find application in creating photonic bound states and exotic photonic states, establishing direction-dependent phase shifts, and studying many-body phenomena in a controllable setting.

References

[1] N. Tomm et al., Phys. Rev. Lett. 133, 083602 (2024).

[2] N. Tomm, et al., Nat. Nanotechnol. 16, 399–403 (2021).

[3] N.O. Antoniadis, et al., npj Quantum Inf. 8, 27 (2022).