Two-Dimensional Coherent Spectroscopy (2DCS) is an advanced optical technique that provides deep insights into the ultrafast dynamics and interactions of complex material systems. By using sequences of ultrafast laser pulses, 2DCS captures information about how electronic and vibrational states evolve over time, revealing crucial details about coherence, energy transfer, and coupling mechanisms within a material.

In semiconductor nanostructures, such as quantum dots, quantum wells, and nanowires, 2DCS is particularly valuable for studying excitonic processes, carrier dynamics, and phonon interactions with high spectral and temporal resolution. The technique helps to disentangle homogeneous and inhomogeneous broadening effects, providing a clearer picture of the underlying physical processes that govern material behavior.

Beyond semiconductors, 2DCS has broad applications in fields such as photosynthetic systems, molecular aggregates, and emerging quantum materials. Its ability to map complex interactions in both time and frequency domains makes it a powerful tool for advancing our understanding of light-matter interactions, ultimately contributing to the design of next-generation optoelectronic devices and quantum technologies.

Anharmonic Oscillator Model for Exciton-Exciton Interactions

In our research, we investigated exciton-exciton interactions in semiconductor nanostructures using the anharmonic oscillator model. We established a direct comparison between the anharmonic oscillator model and the modified optical Bloch equations through simulations of two-dimensional coherent spectroscopy. By demonstrating the empirical equivalence of these complementary models, we provided a quantitative framework for interpreting experimental data related to many-body interactions in excitonic systems. Our findings contribute to a deeper understanding of nonlinear optical responses and have potential applications in optimizing the performance of optoelectronic and quantum devices. DOI

Arbitrary Lineshape Analysis

 In case of simulating 2D spectra, generally, we multiply a Gaussian distribution for inhomogeneity in the emitted 2D signal. To account for an inhomogeneous distribution of frequency, the obtained signal for a homogeneous system is integrated over a 2D distribution function. Starting with a two-dimensional elliptical Gaussian function for the excitation and emission frequency, we simulated the 2DCS signal