Prakriti Joshi

Harnessing collective nuclear vibrations – phonons – can drive emergent behaviors in solids, carry quantum information across surfaces, and reshape design paradigms for quantum and energy materials. Phonons are lower-energy than electronic states, but their interactions with electrons, photons, and other quantum systems can significantly alter macroscopic behaviors, including long-range charge, ion, and heat transport. To directly access and control these phonon-driven processes, we are advancing time-resolved optical spectroscopy – used to probe electronic and vibrational dynamics – into the realm of nanoscale electron microscopies via time-resolved photoemission microscopy (TR-PEEM) and ultrafast transmission electron microscopy (UEM). These new directions in vibrational spectro-microscopy enable the interrogation of elusive nanoscale phenomena, including hidden phase transitions, solid-state ion solvation, and strain-mediated phonon transport.

For a full list of publications, please see Google scholar profile 

† denotes equal author contribution 

1. P. P. Joshi,D. G. Unruh. N. Mirzajani, T. E. Gage, L. Wang, R. Li, H. Liu, L. Liang, I. Arslan, M. K.Y. Chan, S. B. King. Lattice-anisotropy driven reduction of phonon velocities in black phosphorus. ACS Nano. 2025, 19 (4), 4324-4332. 

2. P. P. Joshi †, R. Li. †, J. L. Spellberg, L. Liang, S. B. King. Nanoimaging of the Edge-Dependent Optical Polarization Anisotropy of Black Phosphorus. Nano Lett.2022, 22, 3180-3186.  

3. S. F. Maehrlein†, P. P. Joshi†, L. Huber, F. Wang, M. Cherasse, Y. Liu, D. M. Juraschek, E. Mosconi, D. Meggiolaro, F. De Angelis, X.-Y. Zhu. Decoding ultrafast polarization responses in lead halide perovskites by the two-dimensional optical Kerr effect. PNAS, 2021, 118(7),e2022268118. 

4. P. P. Joshi, S. F. Maehrlein, X.-Y. Zhu. Dynamic Screening and Slow Cooling of Hot Carriers in Lead Halide Perovskites. Adv. Mater. 2019, 180354, 1-10.