Group meetings
The group meets on Wednesdays at 17:00 in the Seminar Room of the Physics Building (2nd floor). Group members, students and visitors present their work, a paper or a tutorial.
Previous meetings
2026
Quantum certification and random quantum circuit sampling
Nadir Samos · Seminar Room, Physics Building (2nd floor)
Current Statistics in Dephased Quantum Chains
João Costa · Seminar Room, Physics Building (2nd floor)
Non-equilibrium steady states of dissipative collective spins
Polina Kofman · Seminar Room, Physics Building (2nd floor)
An introduction to Toeplitz matrix methods: entanglement in non-Hermitian free-fermion chains
Francisco Dias · Seminar Room, Physics Building (2nd floor)
Measurement-Induced Phase Transitions in a Hybrid Quantum-Classical Model
Tiago Jorge · Sala de Formação Avançada, Physics Building (2nd floor)
Sequential strategy for depolarizing strength estimation
Yasir Mehmood · Seminar Room, Physics Building (2nd floor)
Using Landscape Localization theory and Agmon distances to study discrete disordered systems
Adrian Cabral · Seminar Room, Physics Building (2nd floor)
Towards quantum simulations of in- and out-of-equilibrium plasmas and strong field QED
Oscar Amaro · Seminar Room, Physics Building (2nd floor)
Kardar-Parisi-Zhang Equation
Rodrigo Raimundo · Seminar Room, Physics Building (2nd floor)
TutorialSuperdiffusive vibrational energy transport in one-dimensional materials with structural defects: longitudinal to transverse phonon scattering leads to κ ∝ L^{1/3} law
Alexander Burin · Seminar Room, Physics Building (2nd floor)
Non-equilibrium dynamics of dissipative strongly-correlated quantum matter
Gabriel Almeida · Seminar Room, Physics Building (2nd floor)
MSc thesisClassical and quantum memories with LDPC codes
Jacopo Gliozzi (UIUC) · Seminar Room, Physics Building (2nd floor)
Long-range entanglement and (de)localization
Amanda Gatto Lamas (UIUC) · Seminar Room, Physics Building (2nd floor)
Abstract
A result by Gioia and Wang [Phys Rev X 12, 031007 (2022)] showed that translationally symmetric states having nonzero momentum are necessarily long range entangled (LRE). In this talk, I will consider the question: can a notion of momentum for non-translation symmetric states directly encode the nature of their entanglement, as it does for translation symmetric states? We show that this is the case for states in 1D systems with periodic boundary conditions, where localization properties serve as a proxy for entanglement properties. We show how, for 1D systems with periodic boundary conditions, the magnitude |<T>| and phase arg<T> of the expectation value of the translation operator encode (de)localization and entanglement properties of states which break translation symmetry. In particular, we show that, in the continuum limit, |<T>| -> 1 for delocalized states, a proxy for LRE states in 1D systems. This result can be seen as a momentum-space version of Resta's formula for the localization length. We investigate how accurate our results are in different lattice models with and without well-defined continuum limits.
Cutoff thermalization for Ornstein-Uhlenbeck systems with small Lévy noise in the Wasserstein distance
Gerardo Barrera (IST Mathematics) · Seminar Room, Physics Building (2nd floor)
Many-body quantum chaos in quantum platforms
Filippo Ferrari (EPFL) · Sala Reuniões de Física
SeminarGeneralized Time-Translation Invariance and Physical Ageing
Malte Henkel (Université de Lorraine, Nancy) · Seminar Room, Physics Building (2nd floor)
Abstract
Physical ageing out of equilibrium is characterized by slow dynamics, the absence of time-translation invariance, and dynamical scaling. However, we shall show that a generalised form of time-translation invariance allows one to recover the known generic phenomenology of ageing. This behaviour arises in classical many-body systems after a rapid quench from an initially disordered state to a temperature T ≤ T_c, i.e., at or below the critical temperature T_c. Generalised time-translation invariance is obtained, out of equilibrium, through a change of representation of the generators of the Lie algebra of dynamical symmetries associated with scale invariance and time-translation invariance.
The Physics of Associative Memories II - Replicas of the Hopfield model
Paulo Mourão (Sapienza University of Rome) · Seminar Room, Physics Building (2nd floor)
Unitary modular tensor categories for quantum double models
Rafael Torres · Seminar Room, Physics Building (2nd floor)
Kardar-Parisi-Zhang and glassy properties in 2D Anderson localization: eigenstates and wave packets
Sen Mu (MPI PKS, Dresden) · online
Transport through a critical magnetic quantum dot away from equilibrium
Tiago Jorge · Seminar Room, Physics Building (2nd floor)
MSc thesisInitial-State Typicality in Quantum Relaxation
Gabriel Almeida · Seminar Room, Physics Building (2nd floor) · Paper
Paper presentationThe Physics of Associative Memories
Paulo Mourão (Sapienza University of Rome) · Seminar Room, Physics Building (2nd floor)
Self-consistent theory of localization (part II)
Giuseppe De Tomasi · Seminar Room, Physics Building (2nd floor)
Genuine quantum scars in many-body spin systems
Andrea Pizzi (University of Cambridge) · Seminar Room, Physics Building (2nd floor)
Abstract
Chaos makes isolated systems of many interacting particles quickly thermalize and forget their past. While this picture applies to simple observables such as order parameters and correlators, it need not extend to more complex quantities like wavefunction amplitudes, that are becoming accessible in quantum computers and simulators and can reveal a richer structure. In this talk, I will show that although the quantum eigenstates are thermal and strongly entangled, many of them are genuinely scarred, that is, have an enlarged amplitude along underlying classical unstable periodic orbits. For a wide family of spin models, scarring produces non-Porter-Thomas amplitude statistics and makes the system more likely to revisit the orbit it was initialized on, retaining memory of its past and weakly breaking ergodicity. Some features of scarring even extend beyond periodic orbits, giving rise to "quantum trails" along generic trajectories. These findings prove structure in spite of chaos in many-body quantum systems.
Self-consistent theory of localization
Giuseppe De Tomasi · Seminar Room, Physics Building (2nd floor)
Informal discussion on the Information Flow in Monitored Systems
Pedro Ribeiro · Seminar Room, Physics Building (2nd floor)
Quantum thermodynamics with quasiprobabilities: Non-positive energy quasidistributions in coherent collision models
Marco Pezzutto · Seminar Room, Physics Building (2nd floor) · Paper
Based on Pezzutto, De Chiara, Gherardini, Quantum Sci. Technol. 10 035066 (2025)Narrow-band projection in 1D quasiperiodic systems
Flávio Riche · online
Integrability and single particle localization in Krylov space
Clayton Peacock (New York University) · Seminar Room, Physics Building (2nd floor)
Excitations in moiré fractional Chern insulators
Miguel Gonçalves (Princeton University) · Seminar Room, Physics Building (2nd floor)
2025
Microscopic screening theory for excitons in two-dimensional materials: A bridge between effective model and ab initio descriptions
Pedro Ninhos (University of Southern Denmark) · Seminar Room, Physics Building (2nd floor)
Brief review of Kitaev quantum double models
Paul McClarty (Max Planck Institute) · Seminar Room, Physics Building (2nd floor)
TutorialHow to deal with noise in quantum computers
Polina Kofman · Seminar Room, Physics Building (2nd floor)
Non-Hermitian many-body localization: singular value decomposition and transport properties
Federico Balducci (Max Planck Institute) · Seminar Room, Physics Building (2nd floor)
Abstract
In isolated systems, localization and chaos are defined through a web of relations among eigenvalues, eigenvectors, and real-time dynamics. These may change as the system is made open. In this talk, I discuss some recent results on the fate of many-body localization in open systems described by a non-Hermitian Hamiltonian, which can be obtained from Markovian dynamics conditioned on null measurement. First, I show how the singular value decomposition can be used as an effective tool for characterizing dynamical phases, with a crossover of the singular value statistics from Wigner-Dyson to Poisson, and of the singular vectors from delocalized to localized. Second, I shift the focus to dynamical probes, specifically the steady-state spin current, and investigate transport properties. I show that the steady-state current in an interacting Hatano-Nelson model remains finite at all accessible disorders, with no evidence of a transition. These results reveal a stark discrepancy between spectral and singular indicators on one side, which suggest localization, and transport behavior on the other side, which indicates delocalization.
Review of spontaneous breaking of continuous symmetries in 1D quantum systems
Paul McClarty (Max Planck Institute) · Seminar Room, Physics Building (2nd floor)
TutorialA two-stage solution to quantum process tomography: error analysis and optimal design
Carlos Couto · Seminar Room, Physics Building (2nd floor) · Paper
Long-Range Toric Code: Finite-Temperature Topological Order in Two Dimensions
Jacopo Gliozzi (UIUC) · Seminar Room, Physics Building (2nd floor)