Generation of optical Schrödinger "cat" and entangled states using strongly laser driven atoms*

Strong laser physics (SLP) and quantum-optics (QO), are two research directions founded on the classical and quantum description of the electromagnetic radiation, respectively. SLP is based on the use of high power lasers and has led to fascinating discoveries ranging from particle acceleration to attosecond science. On the other hand, QO which largely relies on the use of low photon number sources, has opened the way for groundbreaking achievements in quantum technology (QT) advancing studies ranging from fundamental test of quantum

theory to quantum information (QI) processing. Despite the tremendous progress, until recently SLP and QO remained disconnected. This is because, the majority of the interactions in SLP were successfully described by semi-classical approximations treating the electromagnetic field classically, as there was no need to include the quantum properties of

the field to explain the observations. Here, I will present how we have recently managed to connect SLP and QO and build the foundations for the development of a new class of non-classical light sources for applications in QT. Specifically, I will discuss how fully quantized approaches and conditioning operations in strongly laser driven atoms and HHG process, can be used for the generation of optical Schrödinger "cat" states and entangled light states with controllable quantum features [1-5]. The findings open the way for a numerous of new investigations stemming from the symbiosis of SLP, QO and QI science.

References

[1] M. Lewenstein, et al., Nat. Phys. 17, 1104 (2021).

[2] J. Rivera-Dean, et al., Phys. Rev. A 105, 033714 (2022).

[3] P. Stammer, et al., Phys. Rev. Lett. 128, 123603 (2022).

[4] P. Stammer, et al., PRX Quantum 4, 010201 (2023).

[5] U. Bhattacharya, et al., arXiv:2302.04692.