Room 112
IWDS26 - Program
June 15–19, 2026
McGill University, Dept. of Physics, 3600 rue University
Day 1
Monday, June 15
Opening Day
Room 103
Room 112
Room 112
Eric Heller
30 minRoom 103
Room 103
Lea Santos
30 minRoom 103
Lena Simine
30 minRoom 112
Room 103
Gian Luca Giorgi
30 minDay 2
Tuesday, June 16
Daytime talks · Workshop reception
Room 103
Anton Burkov
30 minRoom 103
Room 103
Room 103
Morgan Thinel
30 minRoom 103
Room 112
Room 103
Enrique Diez Fernandez
30 minRoom 103
Day 3
Wednesday, June 17
Morning talks · Afternoon excursion
Room 103
Marcelo Lyra
30 minRoom 103
Clement Fortin
30 minRoom 103
Room 103
Meet at 12:00 in the Bell room (103), 3600 rue University.
Day 4
Thursday, June 18
Day talks · Poster session · Workshop dinner
Room 103
Luca Tessieri
30 minRoom 103
Tsampikos Kottos
30 minRoom 103
Room 103
Ulrich Kuhl
30 minRoom 103
Mario Amado
30 minRoom 112
Room 103
Défi Junior Jubgang Fandio
30 minRoom 103
Ayana Sarkar
15 minRoom 103
Day 5
Friday, June 19
Closing session
Room 103
Room 103
Jonathan Torres
30 minRoom 103
Abstracts
Click any talk title in the program above to jump directly to its abstract.
Welcome to IWDS26, disorder and topology
Michael Hilke
McGill University · Canada
Authors: Michael Hilke
Opening welcome, history of IWDS and the interplay of disorder and topology.
Back to program ↑Planckian Diffusion, and Electron Transport in Normal and Strange Metals
Eric Heller
Harvard Unuiversity · United States
Authors: Eric J. Heller, Anton Graf, Yubo Zhang, Alhun Aydin, Joonas Keske Rahkonen
By passing to the coherent state limit of quantized lattice waves (quantum acoustics), 65 years after the analogous step in quantum optics, a trove of new and nonperturbative insights emerges, hidden in the traditional second-quantized number-state representation. Planckian diffusion appears as a new universality, emerging as a ghost of Anderson localization after its demise under random medium time evolution. Linear-in-temperature resistivity follows over decades of temperature variation in the strange metals, at the Planckian slope, directly from this universal diffusion. A structural issue has gone unnoticed in the standard treatment of metal resistivity for nearly a century: imposing momentum conservation on electrons plus internal lattice modes is not legitimate once the lattice center-of-mass recoil has been discarded. Restoring it in discrete chunks of reciprocal lattice vector G - umklapp - is ad hoc and it skews the dynamics. The van Hove theory of slow and fast electron, neutron, and UV light diffraction has long done this correctly, and when the center of mass and the full density-density electron-lattice interaction are restored, the theory of metallic resistivity arrives at the dynamical structure factor formalism, normalized.
Back to program ↑Dissipation as a Resource: From Transient to Steady-State Chaos
Lea Santos
University of Connecticut · United States
Authors: Lea F. Santos
Ginibre statistics is often taken as an indicator of dissipative chaotic dynamics. However, we have shown that the Grobe-Haake-Sommers conjecture, which associates Ginibre statistics with chaos and 2D Poisson statistics to integrability, can break down. Our results indicate that Ginibre correlations primarily capture short-time dynamical instability, and therefore signal transient, rather than steady-state, chaos. We demonstrate that the quantum-classical correspondence can be restored by adopting a dynamical perspective based on information scrambling. In particular, diagnostics such as the von Neumann entropy and out-of-time-ordered correlators distinguish transient from long-time chaotic behavior. Building on these findings, we further show that dissipation can serve as a tool to regulate the duration of chaotic dynamics and information scrambling, enabling the recovery of coherence at long times.
Back to program ↑Electronic transport and localization in amorphous graphene
Lena Simine
McGill University · Canada
Authors: Lena Simine
Amorphous materials form a vast, yet vastly underutilized, class of materials. Computational simulations help in making some sense of their properties, but for the most part, the reach of computational methods remains limited. Within this scope, amorphous graphene presents an interesting challenge - to establishing a quantitative relationship between the precise atomistic configuration and electronic conduction requires scaling up to the mesoscale at once the configuration sampling techniques and the electronic conductance analysis. In this talk, I will explain how we use generative machine learning within the framework of the Morphological Autoregressive Protocol (MAP) to extend nanoscale samples into the mesoscale and the insights we get for the role of morphology in electrical conductivity properties in a family of morphologically resolved 'amorphous' graphenes.
Back to program ↑Exponential concentration and symmetries in Quantum Reservoir Computing
Gian Luca Giorgi
IFISC (Institute for Interdisciplinary Physics and Complex Systems) · Spain
Authors: Antonio Sannia, Roberta Zambrini, Gian Luca Giorgi
Quantum reservoir computing (QRC) has emerged as a promising framework for near‑term quantum machine learning, offering in‑memory processing, platform versatility across analogue and digital systems, and freedom from common trainability issues such as barren plateaus and local minima. The exponential number of independent features of quantum reservoirs could, in principle, deliver a performance advantage over classical approaches. However, this exponential scaling can be hindered by exponential concentration: finite‑ensemble noise in quantum measurements forces an exponentially large number of samples to extract meaningful outputs, which represent a well‑known bottleneck in many quantum machine learning models. In this work, we move beyond static tasks and address concentration in QRC for time‑series processing with quantum‑scrambling reservoirs. We show that while scrambling dynamics efficiently propagate information across the system, they also exponentially suppress the distinguishability of output observables, making the algorithm resource‑inefficient. On the positive side, we demonstrate that incorporating Hamiltonian symmetries dramatically mitigates this effect. By analysing the structure of symmetric subspaces and proving rigorous concentration bounds, we establish that symmetries are not just helpful but necessary for scalable and robust QRC implementations.
Back to program ↑Dynamic and Finite Temperature Entanglement Properties of Antiferromagnetic Quantum Spin Chains With Random Long-Range Couplings
Stefan Kettemann
Constructor University Bremen · Germany
Authors: Stefan Kettemann, Javad Vahedi, Andrey Ustyuzhanin
Analytical and Numerical Results obtained with a Real Space Reformulation of the Strong Disorder Renormalization Group Method and Attempts to Teach it to a Dumb Machine
We extend the recently introduced [1,2] strong disorder renormalization group method in real space, well suited to study bond disordered antiferromagnetic power law coupled quantum spin chains, to study excited states, and finite temperature properties. First, we apply it to a short range coupled spin chain, which is defined by the model with power law interaction, keeping only interactions between adjacent spins. We show that the distribution of the absolute value of the couplings is the infinite randomness fixed point distribution. However, the sign of the couplings becomes distributed, and the number of negative couplings increases with temperature T. Next, we derive the Master equation for the power law long range interaction between all spins with power exponent α. While the sign of the couplings is found to be distributed, the distribution of the coupling amplitude is given by the strong disorder distribution with finite width 2α, with small corrections, as long as α>2 [2]. Resulting finite temperature properties of both short and power law long ranged spin systems are derived, including the magnetic susceptibility, concurrence and entanglement entropy dynamics after a quantum quench[2]. We discuss the application of the strong disorder RG to quantum spin systems in higher dimensions.
We next report on our recent attempts to train machine learning algorithms to infer the entanglement structure of disordered long-range interacting quantum spin chains by learning from the strong disorder renormalization group (SDRG) method [3].
[1] S. Kettemann, Strong Disorder Renormalization Group Method for Bond Disordered Antiferromagnetic Quantum Spin Chains with Long Range Interactions: Ground State Properties, Phys. Rev. B 112, 214205 (2025).
[2] S. Kettemann, Finite-temperature properties of antiferromagnetic quantum
spin chains with random long-range couplings, Phys. Rev. B 113, 134204 (2026).
[3] A. Ustyuzhanin, J. Vahedi and S. Kettemann, Machine Learning the Strong
Disorder Renormalization Group Method for Disordered Quantum Spin Chains submitted to Machine Learning in Science and Technology, https://arxiv.org/abs/2603.05164v1
Disordered Weyl semimetal as an array of coupled Hubbard chains
Anton Burkov
University of Waterloo · Canada
Authors: Jinmin Yi, A.A. Burkov
We demonstrate that a disordered magnetic Weyl semimetal may be mapped onto a two-dimensional array of coupled replicated Hubbard chains, where the Hubbard U is directly related to the variance of the disorder potential. This is a three-dimensional generalization of a similar mapping of the two-dimensional quantum Hall plateau transition to a one-dimensional Hubbard chain. We demonstrate that this mapping leads to the conclusion that the Weyl semimetal becomes a diffusive metal with a nonzero density of states at arbitrarily weak disorder, in agreement with recent work. We also discuss the absence of localization in strongly disordered Weyl semimetals from the viewpoint of this mapping.
Back to program ↑Topological quantum phenomena in quantum spin Hall insulator InAs/GaSb heterostructures
Wei Pan
Sandia National Labs · United States
Authors: Wei Pan
Semiconductors have been the “go-to” material over the past five decades for classical information science and microelectronics technology. They may very well continue their primacy in the quantum era. Indeed, by making semiconductor heterostructures a new quantum materials platform, future quantum information science (QIS) and quantum microelectronics applications can build on, and be compatible with, the sophistication and maturity of state-of-the-art semiconductor synthesis and processing. In this talk, I will present our recent work aiming to advance the field of artificial quantum materials for QIS and quantum microelectronics by exploring electron correlation physics and topological phenomena in artificial quantum materials composed entirely of compound semiconductor InAs/GaSb heterostructures. We will show that these artificial quantum materials can enable discovery of new topological quantum phenomena.
Back to program ↑Quantum Localization in a van der Waals Metal
Morgan Thinel
Harvard University · United States
Authors: Morgan Thinel
Localizing electrons is a fundamental pursuit in physics. Normally, the precise control of quantum states relies on the localization of quantum energy levels within a spectral vacuum. Single atoms trapped by optical tweezers as well as defect states trapped in the bandgap of insulating materials are two common approaches to the design of qubits. Thus, metallic materials without a bandgap are commonly understood as antithetical to localization. In this talk, we use scanning tunneling microscopy and spectroscopy to investigate nanoscale quantum localization in a metallic material. First, I will present a new approach to the quantum localization of bound states in the continuum via hopping interference in the van der Waals metal Pd5AlI2. Then, I will show that Anderson localization from backscattering interference emerges in this material when it is exfoliated to the two-dimensional limit.
Back to program ↑Wave Localization and Optical Transport Properties in Correlated Disordered Materials with Hyperuniform Scaling
Francesca Intonti
LENS and University of Florence · Italy
Authors: N. Granchi, G. Calusi, K. Stokkereit, M. Lodde, C. Gonzini, A. Fiore, M. Florescu and F. Intonti
Disorder, traditionally viewed as a detrimental element in photonic systems due to scattering losses and poor reproducibility, has undergone a paradigm shift. Over the past two decades, it has emerged as a powerful design parameter when precisely engineered [1,2]. By embedding structural correlations into disordered arrangements, optical transport, density of states, and scattering properties can be tailored in ways unattainable by either perfectly ordered arrangements or random systems [3].
Among these, Hyperuniform Disordered (HuD) materials have gained significant traction owing to their unique statistical and physical properties. Characterized by suppressed density fluctuations at large length scales, HuD structures exhibit a vanishing structure factor in the long-wavelength limit [4], placing them in a functional regime between crystalline order and total randomness. While lacking Bragg peaks and long-range translational symmetry, they possess a \"hidden order\" that profoundly influences wave propagation. In photonics, hyperuniformity enables phenomena typically reserved for periodic media, such as isotropic photonic band gaps [5,6], while maintaining the structural robustness and fabrication tolerance of disordered systems. This combination is ideal for omnidirectional light control, including waveguiding, light confinement, and enhanced emission.
In this work, we leverage HuD designs in slab platforms, optically activated with embedded quantum dots, and employ near-field hyperspectral imaging with sub-wavelength resolution to investigate light localization. We unveil the physical mechanisms leading to various light trapping behaviors, characterizing them by their distinct localization lengths and quality factors [7-11]. The ability to detect different light-confinement regimes in systems at the junction of order and randomness opens new ways for both fundamental physics and the practical application of correlated disordered materials.
[1] D. Balestri et al., Adv.Mat. 31, 1807274, 2019
[2] F. Riboli et al., Nat.Mat. 13, 720, 2014
[3] K. Vynck et al., Rev.Mod.Phys. 95, 045003, 2023
[4] S. Torquato, Phys.Rep. 745, 1, 2018
[5] M. Florescu et al., PNAS 106, 20658, 2009
[6] L.S. Froufe-Pérez et al., PNAS 114, 9570, 2017
[7] N. Granchi et al., Adv.Opt.Mat. 10, 2102565, 2022
[8] N. Granchi et al.,PRB 107,064204,2023
[9] N. Granchi et al.,Front.Phot. 4,1199411,2023
[10] N. Granchi et al.,JEOS 21, 44, 2025
[11] N. Granchi et al.,accepted in LSA 2026
Probing the effects of disorder in GaAs/AlAs superlattices with THz time-domain spectroscopy
Défi Junior Jubgang Fandio
McGill University · Canada
Authors: Défi Junior Jubgang Fandio
GaAs/AlAs superlattices (SLs) have served as a prototypical platform for investigating wave phenomena in periodic media, including acoustic phonon and thermal transport [1,2]. Engineering phonon transport in these systems requires a detailed understanding of how disorder influences phonon propagation. Recent studies reported the localization of zone-folded (ZF) phonons in ErAs-doped GaAs/AlAs SLs at cryogenic temperatures and predicted the persistence of this regime at room temperature [2]. Here, we employ terahertz (THz) time-domain spectroscopy to investigate the effect of ErAs nanodots on phonon transport in GaAs/AlAs SLs at room temperature. A Lorentz oscillator model was used to reproduce the measured THz transmission spectra and to derive an expression relating the coherent phonon amplitude to the experimentally measured dielectric response. Our results reveal that, in ErAs-doped SLs, the THz transmission associated with phonons in the 1.6–2 THz frequency range decays exponentially with increasing SL thickness, yielding characteristic lengths between 550 nm and 1250 nm. These observations are consistent with the expected signatures of phonon localization. Furthermore, the Lorentz model provides access to the refractive index and absorption coefficient of the SLs, enabling a comprehensive characterization of their vibrational and optical properties. This work demonstrates the potential of THz spectroscopy as a direct probe of disorder-induced modifications of coherent phonon transport at room temperature.
[1] Ye, Z. et al. Nature Communications 16, 8436 (2025).
[2] M. N. Luckyanova et al., Sci. Adv., 4: eaat9460 (2018).
[3] M. Nakayama et al., Jpn J. Appl. Phys., 24, 1331 (1985).
Concentration-Free Quantum Kernel Learning in the Rydberg Blockade
Ayana Sarkar
Universite de Sherbrooke · Canada
Authors: Ayana Sarkar*, Martin Schnee*, Sangeeth Das Kallullathil, Roya Radgohar, Mojde Fadaie, Victor Drouin-Touchette & Stefanos Kourtis
Quantum kernel methods (QKMs) provide a compelling framework for quantum machine learning on near-term devices yet generically suffer from exponential concentration — requiring an exponentially large number of measurements to resolve kernel values with the exception of trivial (i.e., classically simulable) kernels. Solving this tension between hardness of classical simulability and trainability remains an open challenge. Here, we propose a QKM that simultaneously evades exponential concentration and resists classical simulation, by leveraging the weak ergodicity-breaking many-body dynamics inherent to the Rydberg blockade in coherently driven neutral atom arrays. We characterize the proposed kernel analytically through an approximate toy model of the underlying quantum dynamics and validate it with extensive numerical simulations on randomly generated datasets. We further demonstrate effective learning on a classical benchmarking dataset, additionally proposing a scheme with which it is implementable on existing neutral atom quantum hardware. Along the way, we uncover novel physical insights into the thermalization of weak ergodicity-breaking systems through the non-stabilizerness of the underlying Rydberg-blockaded dynamics, which directly governs the classical simulability of the proposed kernel. This connection between quantum complexity measures, weak-ergodicity breaking many-body dynamics and design of practically utilizable quantum machine learning algorithms may be of broad interest to the disordered systems community.
Back to program ↑Resonant cavity QED with chiral flat bands
Marcelo Lyra
Instituto de Física - Universidade Federal de Alagoas · Brazil
Authors: E. M. Broni , A. M. C. Souza , F. A. B. F. de Moura, G. M. A. Almeida, M. L. Lyra
Flat bands exhibit high degeneracy and intrinsic localization, offering a promising platform for enhanced light-matter interactions. Here, we investigate the resonant interaction between a two-level emitter and a chiral flat band hosted by a photonic lattice. In the weak-coupling regime, the emitter undergoes Rabi oscillations with a lifted photonic mode whose spatial structure reflects the nature of compact localized states and the onset of Anderson localization. We show that weak hopping disorder induces a delocalization of the lifted mode, whereas the effective emitter–field coupling strength, and the associated mode volume experienced by the emitter, remains protected against structural fluctuations. We illustrate our approach using selected flat-band lattices. Our findings provide a route to flat-band-state preparation via quench dynamics and robust cavity-QED control.
Back to program ↑Asymmetric Lyapunov exponent fluctuations in disordered Kitaev chains
Clement Fortin
McGill University · Canada
Authors: Clément Fortin, Kai Wang and Tami Pereg-Barnea
Topological edge states are widely regarded as robust against disorder, finite-size effects and other local perturbations due to the global nature of topology. Here, we investigate fluctuations their Lyapunov exponents due to disordered chemical potentials in finite systems. In both the static and periodically driven disordered Kitaev chain, we find a broken symmetry in the fluctuations that makes stronger edge localizations exponentially more likely than weaker ones. We demonstrate that this asymmetry is not tied to the topological phase, but rather follows from the transfer matrix structure of tight-binding models. This effect thus endows topological edge states with an additional protection against disorder and persists across a broad class of disorder distribution. We show that this fluctuation asymmetry can be used for engineering and benchmarking small quantum devices.
Back to program ↑Direct Observation of the Three-Dimensional Anderson Transition with Ultracold Atoms in a Disordered Potential
Nicolas Cherroret
Laboratoire Kastler Brossel, CNRS, Sorbonne Université · France
Authors: Xudong Yu, Ke Xie, Hoa Mai Quach, Myneni Niranjan, Sacha Barré, Jean-Philippe Banon, Alain Aspect, Nicolas Cherroret, Vincent Josse
Despite decades of experimental effort, a direct observation of the Anderson phase transition with matter waves in three-dimensional disordered media has remained elusive. Previous experiments with ultracold atoms were limited by strong and uncontrolled energy broadening, leading to indirect, model-dependent, and sometimes inaccurate estimates of the mobility edge separating localized and diffusive states. In this talk, I will present a recent direct observation of the Anderson transition with cold atoms in a laser-speckle disordered potential, enabling a precise and model-independent measurement of the mobility edge. Our approach relies on a novel energy-resolved scheme that prepares atomic matter waves with a narrow energy distribution and tracks their expansion dynamics over long timescales. The resulting measurements are in excellent agreement with state-of-the-art numerical predictions over a wide range of disorder strengths, resolving long-standing discrepancies between earlier experiments and theory. If time permits, I will also discuss perspectives opened by this scheme, including the study of the fate of the Anderson transition in weakly interacting Bose gases and the quantum-to-classical crossover toward the percolation phase transition.
Back to program ↑Localisation and transport in random media with rotational symmetry
Luca Tessieri
Universidad Michoacana de San Nicolás de Hidalgo · Mexico
Authors: Luca Tessieri
We consider Anderson localisation in bi- and tri-dimensional random models with rotational symmetry. We discuss how the study of these models can be related to the analysis of corresponding one-dimensional systems; specifically, we discuss how the random potentials localise the eigenstates along the radial direction and under what conditions the localisation length of the 2D and 3D models coincides with that of their 1D counterparts. We also show how disorder correlations can be used to modulate the transport properties of finite-size systems.
Back to program ↑in-situ Physical Computing
Tsampikos Kottos
Wesleyan University · United States
Authors: Tsampikos Kottos
We show in-situ wave control in complex multi-resonant environments using time- and energy- efficient adjoint optimization. By exploiting multipath scattering, small real-time perturbations are amplified, enabling targeted channel emission, coherent perfect absorption and camouflage. Our approach is applicable to in-door wireless technologies, imaging, power electronic and optical neural networks.
Back to program ↑Nonlinear Scattering and Sensors based on Limit Cycles
Ulrich Kuhl
University Cote d'Azur, CNRS, INPHYNI · France
Authors: Ulrich Kuhl, Alexander K. Stoychev, Xinxin Guo, and Nicolas Noiray
Nonlinear Scattering and Sensing Based on Limit Cycles
I will present acoustic experiments demonstrating transistor-like [1] and diode-like [2] behavior in scattering systems, implemented using a modified police whistle. These functionalities arise from scattering on limit cycles. The observed phenomena are quantitatively captured by a nonlinear Liénard-type oscillator model incorporating saturable gain and linear loss.
If time permits, I will extend this framework to sensing applications in both acoustic and microwave domains. In particular, limit-cycle-based sensors offer a promising route to partially circumvent the signal-to-noise limitations that currently constrain sensors based on exceptional points.
This work is a collaboration with Alexander K. Stoychev, Xinxin Guo, and Nicolas Noiray (ETH Zurich).
[1] Phys. Rev. E 113, 044214 (DOI: 10.1103/1pd2-d45n)
[2] arXiv:2508.14810 (DOI: 10.48550/arXiv.2508.1481)
Electron Hydrodynamics and Geometric Phases in Moiré Graphene Lattices
Mario Amado
University of Salamanca · Spain
Authors: Mario Amado
We report the dual emergence of collective hydrodynamic flow and quantum geometric phenomena in ultra-high-quality monolayer graphene patterned with periodic antidot lattices. This lithographically defined platform provides a deterministic route to engineering electronic spectra and transport regimes traditionally difficult to access in van der Waals heterostructures. By systematically tuning the lattice geometry, we reveal a hierarchy of commensurability features and pronounced Brown-Zak [1,2] oscillations arising from the alignment of the magnetic flux quantum with the superlattice unit cell. Crucially, we demonstrate that the intrinsic geometric phase of the system is directly measurable, with the magnetic field periodicity precisely matching the lithographic patterning. These results show that moiré-like electronic spectra and their associated topological phases can be generated geometrically in single-layer graphene without the need for twist, lattice mismatch, or multilayer stacking. This structural periodicity simultaneously governs the transition from ballistic to collective transport regimes. The inhomogeneous current flow induced by the antidot geometry facilitates the observation of viscous electron fluids, manifested through an enhanced superballistic effect [3]. We find that this superballistic conduction behaves non-monotonically with the magnetic field, proving that the antidot geometry is a superior architecture for realizing hydrodynamic flow. Our findings establish nanopatterned graphene as a clean, tunable, and scalable platform where deterministic real-space design governs both the fundamental geometric phase of the wavefunction and the emergent many-body dynamics of the electron fluid.
Back to program ↑Advanced lithography and straintronics in 2D materials
Enrique Diez Fernandez
University of Salamanca · Spain
Authors: Enrique Diez, Eudomar Henríquez-Guerra, Rafael Luque-Merino, Vito Clericò, Ana Pérez-Rodríguez, Mario Amado , Andrés Castellanos-Gómez , María Reyes-Calvo
Strain engineering has emerged as a versatile and powerful strategy to modulate the electronic and magnetic properties of 2D materials (see ref. [1] and references therein). Thermoplastics like polycarbonate (PC) has been recently used as particularly effective polymers for the transfer of biaxial compressive strain to 2D materials when samples are cooled down to cryogenic temperatures. The high thermal expansion coefficient and large Young’s modulus of PC make this polymer particularly effective for such a purpose. Recently Eudomar Henríquez-Guerra and collaborators [1] demonstrate effective strain-tuning of the magnetic properties in the 2D layered antiferromagnet CrSBr as revealed by a substantial increase of magnetoresistance and saturation fields. In that work, pairs of flakes with similar thickness and geometry, were dry transfer onto either a 250 μm thick PC film or a Si/SiO2 substrate (300 nm oxide layer). Both substrates, with pre-patterned Ti/Au (5nm/45 nm) electrodes and 30 μm channel length fabricated by e-beam evaporation using a metal shadow mask from Ossila Ltd. The exfoliation of monolayer or few-layers flakes of CrSBr, implies a significant reduction of the flake area requiring a channel length smaller of 3 μm. This requirement is also common to many other 2D materials. Micropattern PC substrates with channels of few microns by photolithography is challenging because PC is etched by almost all standard photoresists and also by acetone during the lift-off process. Here we will show a method based on a chromium mask allowing to achieve micropatterns up to 1 micron.
Back to program ↑Connecting entanglement growth with local integrals of motion in the disordered Fermi Hubbard model
Rachel Wortis
Trent University · Canada
Authors: Rachel Wortis, Ahad Nokhostin Helm, Brandon Leipner-Johns
Generically a quantum system initialized in an unentangled state will, under unitary dynamics, rapidly become entangled, a process closely related to information transport and to thermalization. Disorder can suppress the growth of entanglement and result in memory of initial conditions. In non-interacting systems this arises from localization of single-particle states, the occupancy of which is fixed by the initial condition. In interacting systems similar conserved quantities persist, but with the added feature that they are coupled, resulting in entanglement growth which is distinct from both non-interacting localized systems and from generic ergodic systems. The Fermi-Hubbard model has two degrees of freedom per site–charge and spin–and disorder may be present in both of these, with the same or differing strengths. We study the growth of entanglement in this system and determine the distinct contributions of charge and spin degrees of freedom by expanding the Hamiltonian in terms of a set of optimally localized conserved quantities with separate charge and spin character. We find that coupling between charge and spin is significantly weaker than charge-charge and spin-spin coupling. While this separation of timescales is present in all our results, it is only apparent when the strength of the disorder in the two sectors is different.
Back to program ↑Dynamical signatures of Dyson symmetry classes in quantum interacting systems
Jonathan Torres
Institute of Physics, BUAP · Mexico
Authors: Jonathan Torres, Raúl Arotaipe, Cesar Texca
We study the nonequilibrium dynamics of a one-dimensional disordered spin-1\/2 many-body system whose symmetry class can be tuned across the three Dyson Gaussian ensembles by varying model parameters. Going beyond conventional level statistics, we investigate dynamical signatures of these symmetry classes using two observables: the survival probability and the spin density imbalance, which measures the persistence of local spin memory during the evolution. Comparing their time dependence across symmetry regimes, we identify dynamical features that reflect the underlying symmetries and provide a direct connection between quantum chaos indicators and many-body dynamics.
Back to program ↑Poster abstracts - to be announced
To be announced