Junior Quantum Seminar - Linda Mauron/ Mario Di Luca

Please join us for the Junior Quantum Seminar with Mario Di Luca from the Laboratory of Quantum Physics, Topology and Correlations (LQP), EPFL who will give the talk "Measuring fractional charge in graphene using a quantum Hall antidot" and Linda Mauron from the Computational Quantum Science Lab (CQSL), EPFL who will give the talk "Predicting Topological Entanglement Entropy in a Rydberg analog simulator"on Tuesday October 7th from 9h30-11h.

PLEASE NOTE: The Junior Quantum Series are for gathering  the junior quantum community of master's students, PhDs and post-docs at EPFL, to create a non-judgmental space were scientific ideas can be shared between peers. This event is not for Professors or senior researchers. 

ABTRACT: 
1. Measuring fractional charge in graphene using a quantum Hall antidot:
The detection of fractionally charged quasiparticles, which arise in the fractional quantum Hall regime, is of fundamental importance for probing their exotic quantum properties. While electronic interferometers have been central to probe their statistical properties, their interpretation is often complicated by bulk-edge interactions. In this talk, I will introduce a simple gate-defined bilayer graphene antidot that operates in the Coulomb-dominated regime. This platform enables direct detection of quasiparticle charge through straightforward conductance measurements, bypassing the need for more complex techniques. I will show how this approach reveals fractional charge in graphene and discuss how its simplicity and tunability open the door to extending antidot-based measurements to other van der Waals materials, establishing a broadly applicable route to explore the quantum Hall effect.
2. Predicting Topological Entanglement Entropy in a Rydberg analog simulator:
Predicting the dynamical properties of topological matter is a challenging task, not only in theoretical and experimental settings, but also computationally. Numerical studies are often constrained to studying simplified models and lattices. Here we propose a time-dependent correlated ansatz for the dynamical preparation of a quantum-spin-liquid state on a Rydberg atom simulator. Together with a time-dependent variational Monte Carlo technique, we can faithfully represent the state of the system throughout the entire dynamical preparation protocol. We are able to match not only the physically correct form of the Rydberg atom Hamiltonian but also the relevant lattice topology at system sizes that exceed current experimental capabilities. This approach gives access to global quantities such as the topological entanglement entropy, providing insight into the topological properties of the system. Our results confirm the topological properties of the state during the dynamical preparation protocol, and deepen our understanding of topological entanglement dynamics. We show that, while the simulated state exhibits local properties resembling those of a resonating-valence-bond state, in agreement with experimental observations, it lacks the latter’s characteristic topological entanglement entropy signature irrespective of the degree of adiabaticity of the protocol.

BIO: 
Mario Di Luca is a PhD student at the Laboratory of Quantum Physics, Topology and Correlations (LQP) at EPFL. His research focuses on graphene-based quantum Hall interferometry devices, which he uses to investigate the properties of anyonic quasiparticles. He obtained his Bachelor’s and Master’s degrees in Physics from the University of Pisa, as well as the Engineering Diploma from the École polytechnique, where he studied the impact of boron-nitride alignment on graphene.
Linda Mauron is a PhD student at EPFL, at the Computational Quantum Science Lab (CQST) of Prof. Giuseppe Carleo. She obtained her Bachelor’s and Master’s degrees from EPFL. She obtained a MARVEL’s INSPIRE potentials grant for her Master project at Prof. Carleo’s lab, which she is now pursuing with her PhD.