Ajay Ram Srimath Kandada
Wake Forest University, NC·Physics·Early-career
Many experiments that reveal how materials absorb and respond to light must hit the sample with very intense light, because ordinary (classical) light detection is noisy. The strong light can change the very processes being measured, which makes the resulting models of the material ambiguous.
- Fields
Physics
Chemistry
Materials Science
- Topics
excitons
exciton-polarons
two-dimensional metal halides
- Grants
- 1 known grant, through Jan 2029
What they work on
- Measure how excitons couple to lattice vibrations in 2D metal halide perovskites by recording noise in the amplitude and phase of the optical response after launching coherent phonons, to isolate how random lattice fluctuations drive anharmonicity and polaron formation.
- Use spectrally entangled photon pairs transmitted through the material to estimate the exciton dephasing rate (how fast excitons lose coherence) and biexciton interactions, without the complications of multi-order expansion analyses.
- Track exciton population dynamics, carrier thermalization and exciton formation at extremely low excitation densities in a classical pump–quantum probe experiment, so that many-body interactions do not distort the results.
More about the research
This project brings quantum-optical methods, which offer a better signal-to-noise ratio, into ultrafast nonlinear spectroscopy. The aim is to study light-driven processes in materials close to the limit where single photons are absorbed. The test materials are two-dimensional (2D) metal halide perovskites, layered semiconductors that interact strongly with light. In these materials, light creates excitons, bound pairs of an excited electron and the 'hole' it leaves behind. The excitons interact with vibrations of the crystal lattice to form exciton-polarons, excitons 'dressed' by local distortions of the lattice. Better understanding of these processes is expected to guide improvements in the materials' optoelectronic properties.
Why it matters
Metal halide perovskites are being developed for optoelectronic uses, and a clearer picture of how light-generated excitons behave in their 2D forms could guide efforts to optimize these materials. The project also aims to show that quantum-optical detection can measure light-driven processes at very low light levels. This could help researchers avoid the ambiguities that intense light introduces into conventional spectroscopy.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Lin Chen
Northwestern University, IL·Chemistry
Track how charge carriers and excitons localize and evolve in organic metal halide hybrids on femtosecond timescales using ultrafast optical spectroscopy.
Yosuke Kanai
University of North Carolina at Chapel Hill, NC·Chemistry
Discover hybrid metal halide perovskite materials that show room-temperature superfluorescence, a collective burst of coordinated light emission, with colors tunable across the visible spectrum.
Yu Gong
College of Charleston, SC·Physics
Generate and track topological phonons, robust lattice vibrations in crystalline quantum materials, using ultrafast optical spectroscopy and microscopy with extremely short laser pulses.
The school
Wake Forest University: 27 labs on PI Pages, $345M a year on research, 54 research doctorates a year.
Reach out
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