Τμήμα Φυσικής

Ημερομηνία:  10/2/2026

Ομιλητής: Prof.  Efthimios Kaxiras
Harvard University, USA

Τίτλος: Twistronics: the unconventional behavior of electrons in two-dimensional materials with a twist

Περίληψη :  In the past few years, the field of twisted multilayer graphene and other two-dimensional layered materials, including families of insulators and semiconductors, has blossomed to the point of being referred with by a new term, “Twistronics”.  New structures, including multi-layers of successively twisted single layers, mixed layers, and multilayers of multilayers, are being studied experimentally and revealing ever richer behavior.

We discuss theoretical investigations of some representative systems, starting with the iconic twisted bilayer graphene (tBLG) near the so-called magic angle.  Our work is based on first-principles calculations including full relaxation of atomistic degrees of freedom, from which simpler effective Hamiltonian models can be derived to describe the emergent phenomena.  We focus on the realistic representation of single-particle states and how those can be employed in studying many-body physics related to Mott insulator behavior, superconductivity and other manifestations of correlated electronic states.
 

Τόπος:  Κεντρική Αίθουσα Συνεδριάσεων του Τμήματος Φυσικής, στις 2 μμ

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Διαδυκτιακός σύνδεσμος: https://uoa.webex.com/uoa/j.php?MTID=mc4e7af6cda5979bbb6683620bfc78ba7
Meeting number: 2788 231 3727
Password: hAD9TqCXi29

Περίληψη της ομιλίας (με εικόνες) και σύντομο βιογραφικό του ομιλητή

Ημερομηνία:  19/3/2025

Ομιλητής: Prof.  Roberto Maiolino
University of Cambridge

Τίτλος: The population of infant black holes in the early Universe revealed by JWST

Περίληψη : The James Webb Space Telescope is revolutionising most areas of astrophysics. One of the most exciting and puzzling findings has been the discovery of a large population of massive black holes within the first billion years after the Big Bang. Their properties, and in particular their large masses and peculiar spectral shapes, are difficult to reconcile with the standard black hole formation scenarios, and have required the development of new models, which are being tested against the additional constraints that are being provided. JWST has also revealed that the interplay between these early black holes with their host galaxies was probably quite different than what observed at later cosmic epochs, with important implications for the early formation of galaxies and their stellar populations. JWST is also finding an intriguing, large population of dual black holes, which might be in the process of merging, indicating that this might be an additional route for their early growth and also an early source of gravitational waves. The seminar will give an overview of these various findings, highlighting the impressive progress made so far and also the exciting new questions that have been opened, as well as the prospects of tackling them in the coming years.

Διαδικτυακός Σύνδεσμος: https://uoa.webex.com/uoa/j.php?MTID=m210fd663fdb3995d9f181ab9c5b80fb8
Meeting number: 2785 284 2160
Password: 3DPvKesAZ26

Ημερομηνία:  12/2/2025

Ομιλητής: Prof. Merouane Debbah
Khalifa University of Science and Technology, UAE

Τίτλος:  TelecomGPT: Revolutionizing Telecommunications with Large Language Models

Περίληψη : In this talk, we will explore TelecomGPT, a novel framework designed to adapt general-purpose Large Language Models (LLMs) for specialized applications within the telecommunications domain. Leveraging customized pre-training, instruction tuning, and alignment techniques, TelecomGPT addresses unique challenges in telecom, including domain-specific language understanding, code generation, and real-time network optimization. We will delve into the framework's architecture, key benchmarks, and its potential to enhance network management, reduce operational costs, and drive new AI-driven innovations in telecom. The discussion will highlight TelecomGPT's role in transforming the telecommunications landscape, offering unprecedented opportunities for industry advancement and efficiency.

Οι διαφάνειες της ομιλίας του κ. M. Debbah, που ευγενικά παραχώρησε, βρίσκονται εδώ.