【Date and Time】2-July-2025 10:00am (Beijing time)

【Venue】Room 526

【Host】Zhiliang Yuan (BAQIS)

【Title】Quantum energetics & metrology with photon-number encoding

【Speaker】 

Carlos Anton-Solanas is a researcher specialised in experimental quantum optics and quantum materials. he finished his PhD in 2015, under the supervision of Prof. Vina, on III-V semiconductor exciton-polaritons. As a postdoc (IF Marie-Curie 2016-18), he was working in the group of Prof. Senellart between 2015-2019 on quantum optics with semiconductor QDs. Then, he moved to the group of Prof. Schneider, first in Wurzburg (2020), and finally in Oldenburg, where he participated to the creation of the AG Quantenmaterialien. During this period, he worked on nonlinear & quantum photonics with different 2D materials. Since 2022, he leads the QOSS experimental team at the UAM. 

【Abstract】

A two-level system (such as a charged semiconductor quantum dot), excited under a pulsed resonant drive of area , emits photon-number superposition states composed by vacuum and a single-photon in the form cos(θ/2)|0?+sin(θ/2)| 1? .^1,2 Additionally, a sequential two-pulse excitation can generate photon-number encoded time-entangled states of the form1/√2(|0_e 0_l ?+| 1_e 1_l ?) or 1/√2(| 1_e 0_l ?+| 0_e 1_l ?) , where the subindex e and l refer to early and late time-bins, respectively.^3,4 The expansion of this sequential excitation to a three-level system (such as one polarisation cascade of the biexciton-exciton decay) generates entanglement in time and energy,⁵ with prospects to allow secure quantum communication protocols.⁶

In this seminar, I will revisit these works and will discuss ongoing experiments on (1) the photon-number emission from the Ramsey sequence and its connection to quantum energetics, and (2) the constrained metrology performance of photon-number encoded Fibonacci states and alternatives to reach Heisenberg scaling in metrology protocols.⁷

References

1. Loredo, J. C. et al. Generation of non-classical light in a photon-number superposition. Nat. Photonics 13, 803–808 (2019).

2. Karli, Y. et al. Controlling the photon number coherence of solid-state quantum light sources for quantum cryptography. npj Quantum Inf 10, 1–9 (2024).

3. Wein, S. C. et al. Photon-number entanglement generated by sequential excitation of a two-level atom. Nat. Photon. 16, 374–379 (2022).

4.  Alvarez, J.-R. et al. How to administer an antidote to Schrodinger’s cat. J. Phys. B: At. Mol. Opt. Phys. 55, 054001 (2022).

5. Heindel, T. et al. Exploring Photon-Number-Encoded High-dimensional Entanglement from a Sequentially Excited Quantum Three-Level System. Optica Quantum (2024) doi:10.1364/OPTICAQ.538134.

6.  Santos, A. C., Schneider, C., Bachelard, R., Predojevic, A. & Anton-Solanas, C. Multipartite entanglement encoded in the photon-number basis by sequential excitation of a three-level system. Opt. Lett. 48, 6332 (2023).

7. Paulisch, V., Perarnau-Llobet, M., Gonzalez-Tudela, A. & Cirac, J. I. Quantum metrology with one-dimensional superradiant photonic states. Phys. Rev. A 99, 043807 (2019).