Bell's Nonlocality and Gravitation: One of the most important challenges in physics is to formulate a theory of gravity that is compatible with quantum mechanics. Inspired by Bell inequalities and the experiments that test them, we explore the possibility of incorporating nonlocal effects into gravitation. To this end, we propose a new geometric object within the framework of semiclassical gravity. This construction leads to a model that, under suitable conditions, reduces to General Relativity. Finally, we apply the model to laboratory experiments in which the source of gravity is a particle in superposition.

We celebrate the centenary of quantum mechanics with remarkable achievements and tasks still to be accomplished: As the end of 2025 approaches, it is a good time to remind ourselves what motivated the IYQ initiative, to begin to take stock, and to reflect on what it has meant for quantum science and technology. Over the next few days, we will hear from specialists reporting on important advances in their respective fields. In the second part of my talk, I will therefore refer to the fundamentals of quantum physics, which is my own field of research. The IYQ has helped raise awareness of the confusing interpretative landscape that still prevails a century after the birth of quantum formalism. This suggests the need for significant research efforts to contribute to a better physical understanding of quantum phenomena. To conclude, I will present promising results that allow us to move forward in this direction.

Talking Dual-Use of Quantum Technologies: Between Civilian Promise and Military Concerns: What are the future imaginaries of quantum technologies and how should their risks and promises be communicated? This paper examines how dual-use dilemmas in quantum innovation are framed across scientific, governance, and business domains. While atomic technologies set the precedent for dual-use concerns, the quantum field complicates these distinctions in unprecedented ways. Emerging within fast-moving and interconnected ecosystems, quantum technologies blur boundaries between civilian and military, beneficial and harmful, controllable and unpredictable. Dual-use communication often presumes that risks and benefits can be anticipated, thresholds defined, and trajectories managed. In the quantum domain, such assumptions are increasingly under strain. Through an analysis of scientific publications, governance frameworks, and industry reports, we map the emerging discursive landscape of dual-use quantum technologies. We show that, rather than a unified narrative, multiple overlapping and divergent framings coexist, reflecting different ideas about responsibility, utility, and control. By situating quantum technologies against the backdrop of earlier dual-use dilemmas while emphasizing their contemporary complexities, the paper argues for more reflexive and adaptive approaches to communicating risks and values in quantum innovation.

Probing Quantum Dynamics with 2D Infrared Spectroscopy: Two-dimensional infrared (2DIR) spectroscopy has emerged as a powerful tool for investigating ultrafast quantum dynamics in molecular systems. By resolving correlations between vibrational modes across both frequency and time domains, 2D IR provides unique insight into coherence, anharmonicity, and energy transfer processes, all of which are central to understanding quantum behavior. In this talk, I will highlight how 2DIR spectroscopy enables the real-time observation of vibrational coherences from some examples, directly probe off-diagonal spectral features that are signatures of quantum mechanical couplings, dephasing, and entanglement between vibrational states. Understanding how to manage pulse shaping, phase cycling, and multidimensional pulse sequences that enhance the sensitivity of 2DIR.

Structural Fingerprints of TDBC–Ag Plexcitons from NMR, Raman, and DFT: Plexcitons, hybrid states emerging from strong coupling between molecular excitons and plasmonic modes, promise novel routes for energy transport and photonic control. Yet, their performance hinges on the molecular geometry at the metal interface, which remains poorly understood. We present a combined NMR, resonance and THz-Raman, and DFT study of TDBC J-aggregates and their coupling to silver nanocrystals. Our results reveal that in water, TDBC forms staircase-like aggregates with alternating sulfonate side chains, while adsorption to Ag surfaces preserves aggregate fingerprints but introduces pronounced structural disorder. Low-frequency vibrational modes emerge as sensitive markers of aggregation and interfacial binding, with enhancement factors up to 40 for some modes. These structural insights provide spectroscopic handles to diagnose order and disorder in plexcitons, laying the groundwork for rational design of robust polaritonic materials and subsequent photophysics.

Quantum optics and quantum technologies with giant emitters: When studying the interaction between light and matter at the quantum level, it is common to apply the dipole approximation, where atoms or other quantum emitters are assumed small compared to the wavelength of the light. However, recent experiments [1,2] with superconducting qubits (artificial atoms), coupled to surface acoustic waves or microwave transmission lines, have shown that it is possible to realize ”giant emitters”, i.e., quantum emitters that couple to light (or sound) at multiple points that are wavelengths apart. In this talk, I will present an overview of theoretical and experimental work on such giant emitters [3]. In particular, I will explain how the relaxation rate of a single giant emitter can be designed [4] and how multiple giant emitters can interact via a waveguide while remaining protected from relaxation into the waveguide [5]. I will also show experimental data demonstrating these phenomena [2]. Finally, I will give an outlook for how these properties of giant emitters may be used for quantum technologies such as quantum simulation [6], quantum communication, and quantum sensing. [1] Gustafsson et al., Science 346, 207 (2014) [2] Kannan et al., Nature 583, 775 (2020) [3] Kockum, arXiv:1912.13012 [4] Kockum et al., Phys. Rev. A 90, 013837 (2014) [5] Kockum et al., Phys. Rev. Lett. 120, 140404 (2018) [6] Chen and Kockum, Quantum Sci. Technol. 10, 025028 (2025)

Resonances in Non-Relativistic Quantum Electrodynamics: We introduce a new multi-scale analysis method to investigate the spectral properties of non-relativistic quantum electrodynamics with critical coupling. We obtain mathematically rigorous results on the existence of resonances for atoms minimally coupled to the quantized electromagnetic field, without infrared regularization.

LanMac an Academic Space for the Development of Quantum Science and Technologies in Mexico: The National Laboratory of Quantum Matter: Ultracold Matter and Quantum Information (LanMac) was created ten years ago with the aim of promoting the development of theoretical, experimental, and technological research based on the resources offered by Quantum Dynamics. It is comprised of nine laboratories and multiple theoretical groups. Financial resources were initially provided by the National Council of Science and Technology, with a proportional investment from the various participating universities or research centers. This talk will briefly summarize the ongoing projects and the ultimate objectives of each laboratory. Emphasis will be placed on both cutting-edge research and the relevance of LanMac for the training of human resources and the dissemination of fundamental topics related to the development of Quantum Science and Technologies.

Bose and Fermi Polarons in Atom — Ion Hybrid Systems: Charged quasiparticles, dressed by the low-energy excitations of an electron gas, constitute one of the fundamental pillars for understanding quantum many-body effects in various materials. Quantum simulations of quasiparticles arising from atom–ion hybrid systems may provide new insights into unexplored regimes of solid-state physics.In this talk, we focus on ionic polarons, which emerge when charged dopants interact with a Bose–Einstein condensate [1—3] or with a polarized Fermi gas [3]. We demonstrate that even in a comparatively simple setup—charged impurities immersed in a weakly interacting bosonic medium or in an ideal Fermi gas with a tunable atom–ion scattering length—the competition of length scales produces qualitatively different outcomes. In the bosonic case, a highly correlated mesoscopic state emerges, whereas in the fermionic case, a molecular state forms.Using quantum Monte Carlo simulations, we reveal the vastly different polaronic properties of these ionic systems compared to neutral quantum impurities. Unlike neutral impurities, ionic polarons can bind a large number of excitations, leading to a nontrivial interplay between few- and many-body physics. This fundamentally alters the ground-state properties of the polaron. Our results may also shed light on related systems, such as how composite excitons—bound states of an electron and a hole—affect many-body physics when interacting with a two-dimensional electron gas. [1]. Astrakharchik, G.E., LAPA, Schmidt, R. et al. Ionic polaron in a Bose-Einstein condensate. Commun Phys 4, 94 (2021). [2]. Astrakharchik, G.E., LAPA., Jachymski, K. et al. Many-body bound states and induced interactions of charged impurities in a bosonic bath. Nat Commun 14, 1647 (2023). [3]. U. C. Olivas, LAP Ardila and K. Jachymski. Modified mean field ansatz for charged polarons in a Bose-Einstein condensate. . Phys. Rev. A 110, L011301 (2024) [4]. R.Pessoa, S. A Vitiello, LAPA. Fermi polaron in atom-ion hybrid systems. ArXiv:2401.05324 (2024).

The Tracer and the Fermi gas: At cold temperatures, many body quantum systems show interesting features not known from classical gases. One famous example is Bose Einstein condensation, where the correlation between the Bosons leads to a aggregation of Bosons such that there is a macroscopic occupation of the same state. For Fermions one encounters a contrary effect: The correlation between the particles that comes from the anti-systematization works against aggregation. Fluctuations in the gas are heavily suppressed, dissipation and friction of particles entering the gas are heavily reduced. In the talk I will present recent findings on the dynamics of an additional particle - called tracer - interacting with the Fermi gas. The results show that, in fact, the tracer moves freely on a time scale much longer compared to the time scale one gets for a classical gas or a Bose gas.

Topological excitations in spinorial Bose-Einstein condensates: Topological defects are ubiquitous in physics, allowing for the emergence of thermodynamic phases that are robust under continuous deformations, with novel potential applications. In this talk we will discuss the appearance of vortices and Skyrmions, which are typical topological excitations, in 2D spinorial Bose-Einstein condensates interacting with external magnetic fields and, in particular, we will show the derivation of the most general expression for the Skyrmion topological charge for 2D spin textures. We illustrate our results with a variety of different configurations of the magnetic field, within the Gross-Pitaevskii model. We will also argue on the similarities and discrepancies of this topological charge with the Euler characteristic of the Gauss-Bonnet theorem

Dipolar supersolids and lattice gases: Recent experiments on dipolar gases of magnetic atoms and polar molecules are opening interesting new possibilities, which I will briefly discuss in this talk. On one side, experiments on dipolar Bose-Einstein condensates of magnetic atoms have recently created a dipolar supersolid array of quantum droplets, in which superfluidity and crystal-like order coexist. After briefly introducing the idea of quantum droplet and dipolar supersolids, I will discuss in some detail some of our recent results on 2D supersolids and dipolar Bose-Bose mixtures. In the second part of the talk, I will focus on dipolar gases in optical lattices. After discussing the new physics introduced by the dipole-dipole interaction in the physics of quantum gases in optical lattices and tweezer arrays, I will discuss some of our more recent results, including disorder-free localization due to Hilbert-space fragmentation, relaxation dynamics in dipolar spin models, and novel quantum phases in ladder geometries.

Controlling the Current Flow in 2D Quantum Materials: In this talk, we explore various strategies to manipulate and control the electronic transport in 2D quantum materials. We show that the current flow in graphene can be guided on atomically-thin current pathways by the engineering of Kekulé distortions. A grain boundary in these distortions separates the system into topologically distinct regions and induces a ballistic domain-wall state. The state is independent of the orientation of the grain boundary with respect to the graphene lattice and permits guiding the current on arbitrary paths [1]. When considering a graphene bilayer, we demonstrate that it is possible to steer the current by twisting one layer relative to the other. The observed steering gives rise to a non-local Hall resistance and can be explained by the trigonal shape of the energy bands due to the Moiré interference pattern [2]. Additionally, we discuss the emergence of anomalous edge states in this system, which open new possibilities for transport control [3]. [1] Galván y García, et al., Nano Lett. 24, 2322 (2024) [2] Sánchez-Sánchez, et al., J. Phys. Mater. 5, 024003 (2022) [3] Sánchez-Sánchez, et al., Phys. Rev. B 110, 205432 (2024)

Organic molecules as spin-optical interfaces: from quantum sensing to photoredox catalysis The transduction of quantum information from the microwave to the UV-visible range can be surprisingly robust in open-shell organic molecules.  At the heart of this possibility is the observation that small changes in spin dynamics can lead to drastic changes in electronically excited processes. In my talk, I will describe our recent efforts designing organic molecules whose ground-state properties can be exploited for magnetometry, serving as organic analogues of NV centers [1,2,3]; some of the predictions have been demonstrated by recent experiments of the Wasielewski group [4,5]. These examples provide clear evidence that chemical design can serve to augment the toolbox of quantum information. Conversely, I will conclude by suggesting that the opposite should also be true: subtle control of spin dynamics should lead to dramatic changes in chemical behavior in appropriately designed schemes for photoredox catalysis, and in particular, for enantiopurification [6].