Quantum Information and Computation for Particle Physics day

Thursday 18 Dec 2025, 09:00 → 17:00 Europe/Madrid

Seminario Fisica Teorica 2nd Floor (Departamento Fisica Teorica)

 

An informal local gathering to listen to recent developments at the cross roads of Quantum Information and Computation with Particle Physics (collider based or not).

 

No inscription fee is required, but registration is requested. Please direct inquiries to Felipe J. Llanes-Estrada, fllanes@fis.ucm.es

 

A Google Meet link will be made available to registered participants at the email which they used to register, so they can follow online any talks they are interested in.

09:00 → 10:20 Talks

09:00 Presentation and overview of quantum computation in hadron physics

I will quickly cover a few highlights of problems where quantum computing can have an impact in hadron physics, and show some illustrative extant calculations.

Speaker: Felipe J. Llanes-Estrada (Universidad Complutense de Madrid)

LlanesEstradaQIday.pdf

09:20 Quantum entanglement negationism

Two papers 2507.15947 and 2507.15949 have claimed that quantum entanglement cannot be measured at colliders. I will discuss what is locality, what is entanglement, and show how confused the authors are.

Speaker: Juan Antonio Aguilar Saavedra (IFT UAM-CSIC)

QEnegationism.pdf

09:50 Quantum algorithms for bosonic Hamiltonians and applications to lattice field theory

The strong nuclear force, described by the theory of quantum chromodynamics (QCD), controls the behavior of quarks and gluons—the fundamental constituents of most visible matter. Despite decades of theoretical and experimental progress, many key questions remain unresolved: How do the dynamics of quarks and gluons give rise to emergent structures such as nucleons and nuclei? What is the phase diagram of nuclear matter, and what are the real-time and non-equilibrium dynamics at collider experiments and in the early universe? Although perturbative methods and lattice QCD have advanced our understanding, some of the most demanding problems lie beyond the reach of classical computation. Recent developments in quantum computing, together with new algorithmic strategies, offer promising avenues for tackling these challenges. One of the most challenging aspects of quantum simulations in fundamental physics is the preparation of ground states, which I will focus on in this talk. Specifically, I will discuss the development of adaptive variational algorithms (ADAPT-VQE) for bosonic Hamiltonians. These techniques not only accelerate and improve variational simulations compared to traditional approaches for lattice field theory, but also have broad relevance across condensed matter physics, quantum chemistry, and other strongly correlated quantum systems.

Speaker: Gloria Tejedor Garcia (Stony Brook University)

SLIDES DECEMBER BOSONIC HAMILTONIANS.pdf

10:20 → 10:50 Break

10:50 → 13:00 Talks

10:50 Quantum Colliders

Quantum Mechanics is the fundamental theory of the microscopic world, developed at the beginning of the 20th century. The study of quantum foundations and the classical-quantum frontier is still nowadays an active field of research, with direct applications in quantum technologies. However, little attention has been devoted to experimental tests of quantum signatures at relativistic energies, even though it is a subject of fundamental interest. We discuss how high-energy colliders can become a unique laboratory for such purposes. We focus on the paradigmatic case of a top-antitop quark pair, a drosophila of a relativistic two-qubit system, since its quantum state can be fully reconstructed from the angular distribution of the decay products. We discuss how quantum correlations, such as entanglement, can be studied in high-energy colliders using top-quark pairs, including recent measurements by ATLAS and CMS. Finally, we outline future avenues for the development of the exciting field of quantum colliders.

Speaker: Juan Ramón Muñoz de Nova (Universidad Complutense de Madrid)

Quantum_Colliders_UCM.pdf

11:40 Simulation of fragmentation functions on Quantum Computers

The real-time phenomenology of QCD remains elusive to traditional computational techniques based on Monte Carlo sampling in Euclidean space. In contrast, on Quantum Computers the time evolution is in principle possible because the basic gates form a universal set of unitary transformations.

In this context, we discuss the calculation of fragmentation functions, key to describe how quarks and gluons transform into observable hadrons. As we move along we introduce a series of strategies to face the problem using quantum computers, all grounded in a codification paradigm where particles and their internal degrees of freedom are the central objects.

Speaker: Juan José Gálvez Viruet (Univ. Complutense de Madrid)

JJGV_181226.pdf

12:10 Entanglement: A possible source of information on nuclear structure

Entanglement offers a compact and quantitative way to characterize correlations in quantum many-body systems, and can therefore provide new information on nuclear structure beyond standard observables. In this talk I discuss how quantum-information concepts—focusing on spin entanglement—can be connected to few-body nuclear dynamics, with emphasis on two-proton emission. Motivated by recent theoretical predictions of Bell–CHSH inequality violation in the unbound nucleus 6Be, I outline how the decay 6Be →α+p+p can serve as a sensitive probe of proton–proton correlations and decay mechanisms. I also summarize the experimental perspective at R3B/GLAD, where full reconstruction of charged fragments and downstream proton polarimetry can enable access to spin observables and entanglement-related signatures.

Speaker: Youssef KHLIFI (IGFAE_USC)

Khlifi-Madrid .pdf

12:40 Towards quantum simulation of strongly interacting matter in neutron stars

The aim of this work is to constrain the neutron star equation of state (EoS). At the energy densities characteristic of neutron star cores, QCD is non-perturbative and the EoS is currently poorly constrained. Classical methods such as Lattice QCD present limitations when dealing with finite density systems. To address this challenge, we use Quantum Computing techniques to simulate the strongly interacting matter inside the star. We encode relevant QCD degrees of freedom into qubits, which are assigned to each particle in the system.

Speaker: Nahia J. Dios Bilbao

Presentación_18_dec-3.pdf

13:00 → 14:30 Break

14:30 → 16:30 Talks

14:30 Quantum Information in Scattering: from production at future colliders to the structure of fundamental interactions

This talk outlines how ideas from quantum information (QI) help characterize fundamental interactions in high-energy scattering.
First, I will discuss the QI landscape at future colliders, focusing on the Electron–Ion Collider. With transverse beam polarization, electron–proton scattering can produce controllable spin entanglement and non-stabilizer (“magic”) states, offering a concrete setting to study how quantum correlations arise in electroweak theory and QCD.
In the second part, I will broaden the view and examine whether simple QI measures expose recurring patterns across the Standard Model—for example, how entanglement suppression tracks emergent symmetries at low-energy QCD, and how it may also be connected to observed mixing patterns in the flavor sector.
This perspective suggests that QI-theoretic constraints may play a previously unrecognized role in shaping the structure of fundamental interactions.

Speaker: Sokratis Trifinopoulos

15:30 What is a particle in curved spacetime? Groupoids.

A new approach to describe elementary particles in curved space-times will be discussed. Wigner's program is extended by replacing kinematical symmetry groups by its natural generalization to curved space-times: kinematical groupoids. Then, elementary particles are classified according to the irreducible projective representations of the kinematical groupoid of the given space-time. The same background allows to analyse the foundations of relativistic information theory in curved background space-times.

Speaker: L. Alberto Ibort (Univ. Carlos III Madrid)