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Magnetic field emerging from the geometric curvature of quantum structure of electrons in a crystal bends electronic trajectory causing anomalous linear and nonlinear electrical Hall effects that have been observed in low symmetry crystals with no external magnetic field. We present first-principles theoretical analysis to show that dynamical lowering of crystal symmetry by lattice vibrations results in oscillations in the quantum geometry of electrons which have observable nonlinear Hall signatures. We introduce a vibrational spectroscopy based on Geometry of Quantum Electronic Structure (GQuES) making specific predictions for the transport and radiative GQuES spectra of 2D materials and demonstrate its applicability to a wide range of materials and excitations at sub-GHz, THz and infrared frequencies. Ideas in this work connect interestingly with those in the Raman effect and Pancharatnam phase.
Umesh Waghmare received a B Tech (with institute silver medal) in Engineering Physics from the IIT, Bombay (1990) and a PhD in Applied Physics from Yale University (1996). He worked as a post-doctoral research associate in physics department at Harvard University before joining Jawaharlal Nehru Centre for Advanced Scientific Research in 2000, where he is presently a Professor in the Theoretical Sciences Unit and a JC Bose National Fellow.
He is presently distinguished adjunct professor at Temple University, and the President of the Indian Academy of Sciences. He is an Associate Editor of NanoScale and NanoScale Advances. He is a recipient of DuPont Young Faculty grant award (2003), MRSI medal (2004), B M Birla award for Physics (2005), DAE outstanding research investigator award (2009), IBM Faculty Award (2009), SS Bhatnagar prize in Physical Sciences (2010) and the Infosys Prize in Engineering and Computer Science (2015). He was recognized as a distinguished alumnus by IIT-Bombay in 2017. He is a Fellow of Indian Academy of Sciences, National Academy of Sciences, Allahabad, the Indian National Science Academy and Indian National Academy of Engineering.