2D transition-metal dichalcogenides have attracted significant attention due to their unique properties, which make them highly promising for a variety of applications ranging from quantum technologie...

Bi2Se3, a layered three-dimensional topological insulator, exhibits intriguing changes in its band structure when its thickness is reduced below 7 quintuple layers. The reduction in thickness leads to...

QUantum reservoir cOmputing based on eNgineered DEfect NetworkS in trAnsition meTal dichalcogEnides (QUONDENSATE) is a EU Pathfinder project. Today’s computation, based on parallel processing of infor...

2D-Vision 2025 workshop combined the beautiful historic setting of Pisa with high-level scientific discussions. The venues were the prestigious Scuola Normale Superiore and Domus Comeliana, an exquisi...

Jedynka - polskieradio.pl

Quantum confinement and reduced dielectric screening lead to strong excitonic effects in atomically thin transition metal dichalcogenides (TMDs). Encapsulation of TMD monolayers in hexagonal boron nitride (hBN) unveils the excitonic Rydberg series below the free particle bandgap. The nonequilibrium response and the dynamics of these higher order exciton states and their multiparticle complexes remain almost unexplored. Here we use ultrafast pump–probe optical microscopy to measure the dynamics of excited-state (2s) excitons in hBN-encapsulated monolayer WSe2. 2s excitons form through an ultrafast relaxation process from high-energy states and exhibit longer decay dynamics than ground state excitons due to their higher spatial extension. We detect light-induced formation of 2s trions with significant oscillator strength and faster decay dynamics than 2s excitons, attributed to an intra-excitonic Auger effect causing an additional decay channel. Our results shed light on the dynamics of excited state excitons in TMDs and their interactions with free carriers.