Stimulated emission from multilayer graphene

Stationary Two-State System in Optics using Layered Materials

“…The magnitude of F is given by |F | = σ √ A abs , while the sign of F depends on the matter system. [19][20][21] In the same way as |Φ a , the continuity of the electric field with respect to |b , 0|E z (0+)|b = 0|E z (0−)|b , and the physical state condition 0| ⊗ vac|B|Φ b = 0 are sufficient to obtain that…”

“…which can be verified by experiments. 21 Because the two states slightly overlap, i.e., Φ b |Φ a = 0, a simple interpretation of a two-state system is difficult to be applied. Apparently, from the reflected (or transmitted) light we will observe, the signal is inseparable between |Φ a and |Φ b .…”

“…Quite recently, we found also that one can access |Φ b by suppressing the contribution of the other state to the reflection (r ∼ 0) using a multilayer graphene (about 20 layers) and destructive interface effect of a SiO 2 /Si substrate. 21 Note that |Φ b appears as a correction to the reflection (and transmission) coefficient, not as a correction to the dynamical conductivity. Meanwhile, the (spontaneous) emission is generally treated as a loss, and it is often included as the phenomenological relaxation constant in the dynamical conductivity.…”