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New findings associated with TIMES Project
Recent research by Yuncheng Mao and Claudio Attaccalite has uncovered how magnetic fields can dramatically reshape the photovoltaic response of Bernal bilayer graphene. Their study shows that when time-reversal symmetry is broken by an external magnetic field, the material’s spatial symmetry changes, opening the door to new mechanisms for generating electrical current from light. The…
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Coherence Between Incoherent Excitons Revealed by TR-ARPES
A new study linked as a result to the TIMES project presents an exact solution for exciton dynamics in a two-band semiconductor model, capturing the transition from coherent to incoherent regimes. By incorporating light–matter, electron–electron, and electron–phonon interactions, the model reveals how excitonic polarization and coherence evolve under nonresonant below-gap excitation. Using time-resolved angle-resolved photoemission…
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A new TIMES result: direct observation of Floquet–Bloch states in graphene
Floquet engineering has emerged as a powerful way to manipulate quantum phases of matter through periodic driving. While replica bands known as Floquet–Bloch states have been predicted and observed in some materials, direct energy- and momentum-resolved evidence has remained rare. In this new study, researchers report the direct observation of Floquet–Bloch states in monolayer epitaxial…
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First TIMES-linked result are here: from Moiré physics to ultrafast photonics
TIMES Project begins to deliver results and is now starting to bear fruit! We are proud to share some of the very first scientific outcomes with our community. These initial results mark an important milestone, showing how collaborative research within TIMES is opening new pathways in the study of ultrafast phenomena in quantum materials. Layered…
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Exact formula with two dynamically screened electron-phonon couplings for positive phonon-linewidths approximations
Dr. Stefanucci and Dr. Perfetto from University of Rome Tor Vergata as members of the TIMES Project introduced an exact formula for the phonon linewidths involving only dressed electron-phonon couplings and ensuring the positivity property.
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Excitonic Bloch equations from first principles
Dr. Stefanucci and Dr. Perfetto from University of Rome Tor Vergata as members of the TIMES Project published new excitonic Bloch equations. The introduction of an auxiliary exciton species, termed the irreducible exciton, enables to formulate a close set of equations describing exciton dynamics without unphysical overscreening.
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TIMES partner published a theory of coherent phonons coupled to excitons
Last June, 2024, Dr. Perfetto, a researcher at the University of Rome Tor Vergata and member of the TIMES Project, published together with his colleagues Dr. Wu and Dr. Stefanucci a quantum many-body theory for the effective interaction between excitons and coherent phonons. This theory predicts that the exciton energy features a polaronic-like red-shift and…
