Vibro-Polariton States from First Principles

In recent years there has been a number of exciting experimental and theoretical developments in the study of light matter coupled systems. In the strong coupling regime the normal modes of the system can become hybrid states which mix nuclear, electronic, and photon degrees of freedom. Altering the vibrational modes of molecules through strong light matter coupling has been demonstrated to influence chemical reactions in molecular systems [1]. First principles methods capable of treating the light and matter degrees of freedom on the same level of theory are an important tool in understanding the physics of such systems. In this talk we develop and apply a generalized force constant matrix approach to the study of mixed vibration-photon states of molecules within the quantum electrodynamical density functional theory framework. With this method the IR and Raman spectra can be computed via linear response in a manner analogous to techniques widely used for conventional phonons. This enables more efficient computation than previous time dependent approaches [2], with access to additional properties. Extensions of the method to solids and the nonlinear regime will also be discussed.

[1] Anoop et al. Angew Chem Int Ed Engl. 55, 11462 (2016)
[2] Flick et al. PRL 121, 113002 (2018)