Effects of renormalization and non-Hermiticity on nonlinear responses in strongly-correlated electron systems

Understand

Nonlinear responses in condensed matter are intensively studied because they provide rich information about materials and hold the possibility of being applied in diodes or high-frequency optical devices.

• While nonlinear responses in noninteracting models have been explored widely, the effect of strong correlations on the nonlinear response is still poorly understood, even though it has been suggested that correlations can enhance the nonlinear response.
• In this work, we first give an analytical derivation of nonlinear responses using the Green's function methods at finite temperature.
• Then, we discuss the difficulties of considering dissipation using conventional methods, such as the reduced density matrix method.