## Convocazione seminari vincitrici e vincitore procedure selettive RTDA PNRR PE Dipartimento Fisica

Mercoledì 15.03.2023 in aula Rasetti si terranno i seminari delle vincitrici e del vincitore delle ultime procedure selettive per RTDA.

Si potrà partecipare in presenza o in alternativa da remoto in collegamento Zoom :

https://uniroma1.zoom.us/j/85078619957?pwd=R3VkcDNCZXB3dW5uaE5NamxvbDd5dz09

**Ore 15.30 Dr. ssa Taira Giordani vincitrice procedura 2023RTDAPNRR039 02B1 FIS/01**

**Title: High-dimensional quantum photonic platforms**

Quantum information aims at providing an alternative paradigm for information processing based on the laws of quantum mechanics. Several milestone experiments have been carried out in very recent years in many areas, ranging from communications to computing. In this context, quantum optics and photonic platforms are promising solutions for realizing quantum processors.

In this seminar, I illustrate two high-dimensional architectures based on the encoding of the information in the path and in the angular momentum of single photon states. Regarding the latter, I present a bulk quantum walk-based engineering protocol for quantum states in the angular momentum of light together with machine-learning techniques for their reconstruction. On the other hand, integrated photonics is one of the best candidates for compact and scalable realizations of various protocols in quantum information, computation, and sensing. In this case, path encoding is one of the most suitable choices. I present optical chips that can be simultaneously programmed to reach a specific unitary operation, as well as sampling random ones. I also describe the latest methods we developed for benchmarking multi-photon experiments in this kind of devices.

**Ore 16. 00 Dr. ssa Valeria Cimini ****vincitrice procedura 2023RTDAPNRR040 02B1 FIS/01**

**Title: **Quantum-enhanced multiparameter estimation in adaptive regime

Quantum Metrology explores the fundamental and attainable limits on measurement precision when using quantum probes. It pays special attention to situations where the quantum properties of the probe state enable surpassing the best sensitivity achievable with classical probes. One of the most employed figures of merit to assess the quality of the estimation is the quantum Cramèr-Rao bound (QCRB), consisting in the ultimate achievable precision given the employed probe state. However, this quantity is only valid in an asymptotic resource regime. In real scenarios, the number of available probes is usually limited, therefore, to grant the saturation of the QCRB in such limited-data regime, it is necessary to implement an adaptive strategy. This involves optimizing the allocation of probes during the estimation protocol by adjusting measurement settings after each probe interacts with the system under investigation. These optimization tasks can be complex, especially when dealing with multiparameter problems, which are common in practical applications where multiple parameters need to be monitored simultaneously. As a result, multiparameter quantum metrology has gained significant interest in recent years, demonstrating when simultaneous estimation of multiple parameters with quantum entangled probes is superior to their separate estimation. In our works we demonstrate experimentally such an enhancement in the context of optical interferometry. In particular, we develop adaptive multiparameter strategies implemented on integrated photonic interferometers which allow high reconfigurability and easy scalability

**Ore 16.30 Dr.ssa Annalisa D'Arco ****vincitrice procedura 2023RTDAPNRR042 02B1 FIS/01**

**Title: **Quantum Materials for THz & IR photonics

In this talk, I briefly introduce my educational and work experiences. Following, I illustrate my recent research activities in the field of THz/IR photonics and spectroscopy, highlighting the acquired technological and research expertise. Finally, I’ll talk about the future research activity concerning the potentialities of non-conventional materials, quantum materials, as appealing candidates for efficient, durable and robust opto-electronics components capable of generating, modulating and detecting THz/IR radiation

**Ore 17.00. Dr.ssa Ludovica Falsi ****vincitrice procedura 2023RTDAPNRR043 02B1 FIS/03**

**Title: Photonics in the ferroelectric supercrystal phase**

I will provide an overview of the experimental investigation through several optical techniques of so-called supercrystals in nanodisordered ferroelectrics. These are highly regular 3D domain patterns with a micrometer lattice constant that form spontaneously at the Curie point in bulk crystal samples. For optical propagation, these topologically intricate patterns have interesting and hereto little understood properties, such as an anomalous large broadband index of refraction, constraint-free Second-Harmonic-Generation, and the ability to depolarize incoming light into orthogonally polarized sub-lattices. These properties amount to a material that allows highly miniaturized achromatic optical circuitry and strongly enhance nonlinear response, with possible impact in high-resolution imaging and miniaturized integrated optical circuitry. As a product of a 3-axis breaking of inversion symmetry, our experiments on temperature-driven and electric-field-driven domain dynamics also shed light on 3D percolation and 3D topological defects in the spontaneous polarization field.

**Ore 17.30. Dr.**** Michele Rota vincitore procedura 2023RTDAPNRR044 02B1 FIS/03**

**Title: Quantum dot-based sources of entangled light for future quantum networks**

The realization of a quantum network will enable the exchange of qubits between nodes at remote locations widening the range of quantum technologies to potentially worldwide scale.

The best way to exchange qubits in a network is by encoding information in the several degrees of freedom of light quanta, i.e., photons. It is clear that the development of a reliable source of single and entangled photons is becoming a crucial milestone for quantum technology development.

In this seminar, I will introduce semiconductor quantum dots as sources of entangled photons and their exploitation in protocols for quantum communications. I will then show the work devoted in my last years of research to improve the figure of merits of these nanostructures toward their future exploitation in real-life quantum networks. In particular, I will show our latest results with quantum dots embedded into photonic microcavities coupled with a piezoelectric device to apply strain fields.