Abstract
The semiclassical expressions for susceptibilities are inadequate when quantum aspects of light become prominent. A more appropriate formulation of the electrical susceptibility theory requires the quantization of the electromagnetic field. We show here a way to do this up to the second order, within a low-dimensional system. The generalized expressions reveal that susceptibilities depend on the quantum state of light. As experimentally verifiable consequences of this, we predict new phenomena such as photon number-dependent refractive index, even in the linear regime, and non-quadratic second harmonic generation, which should be appreciable when very low-intensity coherent light is involved. We also deduce when the semiclassical expressions, which happen to be particular cases of those derived here, can be used confidently.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
