QuCoLiMa Talk – Brahim Lounis – Tailoring the degree of entanglement of two coherently coupled quantum emitters

Speaker:

Brahim Lounis - University of Bordeaux, France

Title:

Tailoring the degree of entanglement of two coherently coupled quantum emitters

Abstract:

The control and manipulation of quantum-entangled non-local states is a crucial step for the development of quantum information processing. A promising route to achieve such states on a wide scale is to couple solid-state quantum emitters through their coherent dipole-dipole interactions. Entangling the electronic states of coherently interacting solid-state emitters is challenging since it requires both a coupling strength larger than the coherence decay rate, implying nanometric distances between the emitters, and quasi-degenerate optical transitions, detuned by less than their coupling strength. Single aromatic molecules embedded in well-chosen solid matrices at liquid helium temperatures are unique candidates to achieve this goal, as they have proven to be test-bench systems for quantum optics. Due to their random spatial distribution in the host crystal and the variety of local matrix environments that span their optical resonances within an inhomogeneous band, fulfilling the requirements of space and transition-frequency proximities of the molecules remains a challenge.

We use hyperspectral superresolution imaging in highly doped molecular crystals to reveal pairs of coupled fluorescent molecules. We demonstrate the manipulation of the degree of entanglement of coupled molecules through Stark shifts of their optical resonances. We achieve maximal entanglement with nearly pure subradiant and superradiant Bell states. We also show that delocalized molecular electronic states can extend over distances as large as 60 nm, which opens up attractive perspectives in terms of addressability.

Location:

Erlangen

All talks hybrid:

Mixture of on-site talks at the main sites of QuCoLiMa (Erlangen, Mainz, Saarbrücken) as well as online talks. Regardless of where the talks are given, they are livestreamed via Zoom and can be watched from home/office or cooperatively in the meeting rooms.

Zoom-Link:

http://www.qucolima.de/join-qucolima-talk

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QuCoLiMa Talks are regular seminars of the collaborative research center TRR 306 QuCoLiMa (Quantum Cooperativity of Light and Matter), where (external) experts are invited to present their work.

More information at http://www.qucolima.de/talks