arXiv subjects

Alperen Tüğen

Publications and source records attributed to Alperen Tüğen.

3 recordsLinked to original sources

arXiv2026

Interactions of electrons and Rydberg excitons in two-dimensional semiconductors

Rydberg excitons in two-dimensional semiconductors provide sensitive and non-destructive probes of physics in proximal sample layers that host correlated electronic states. In particular, electron or hole doping of the sample layer is heralded by a strong frequency shift and loss of transition strength of 2s excitons in the sensor layer. In analogy to the attractive polaron observed near the 1s exciton, this redshifted resonance, which we term Rydberg attractive polaron (RAP), has been attributed to the formation of a bound state of a 2s exciton and a remote electron. Through a theoretical analysis of exciton-electron scattering, we show that the nature of the RAP and its underlying trion can only be explained by electron-mediated hybridization of 2s, 2p and interlayer excitons, endowing the RAP a different structure than the 1s attractive polaron. We anticipate that this new understanding will ensure a more accurate assessment of the signatures of correlated electrons in two dimensional materials.

cond-mat.mes-hall↗

arXiv2025

Optical Injection and Detection of Long-Lived Interlayer Excitons in van der Waals Heterostructures

Interlayer excitons in semiconducting bilayers separated by insulating hBN layers constitute a promising platform for investigation of strongly correlated bosonic phases. Here, we report an optical method for the generation and characterization of long-lived interlayer excitons. We confirm the presence of tightly bound interlayer excitons by measuring 1s and 2s intralayer excitons in each layer concurrently. Using a pump-probe technique, we find interlayer exciton lifetimes up to 8.8 $μ$s, increasing with the thickness of the hBN. With optical access to long-lived interlayer excitons, our approach provides a new route to explore degenerate Bose--Fermi mixtures of excitons and itinerant electrons with high spatial and temporal resolution.

cond-mat.mes-hall↗

arXiv2018

Demonstration of Optical Nonlinearity in InGaAsP/InP Passive Waveguides

We report on the study of the third-order nonlinear optical interactions in In$_{x}$Ga$_{1-x}$As$_{y}$P$_{1-y}$/InP strip-loaded waveguides. The material composition and waveguide structures were optimized for enhanced nonlinear optical interactions. We performed self-phase modulation, four-wave mixing and nonlinear absorption measurements at the pump wavelength 1568 nm in our waveguides. The nonlinear phase shift of up to $2.5π$ has been observed in self-phase modulation experiments. The measured value of the two-photon absorption coefficient $α_2$ was 15 cm/GW. The four-wave mixing conversion range, representing the wavelength difference between maximally separated signal and idler spectral components, was observed to be 45 nm. Our results indicate that InGaAsP has a high potential as a material platform for nonlinear photonic devices, provided that the operation wavelength range outside the two-photon absorption window is selected.

physics.optics↗