Circular cascades
Circular cascades consist of a system of levels of which one only can be excited at a time, and the flow of this excitation is constrained to (predominantly) go in one direction, eventually coming back to where they started (whence the circularity). As a result, peculiar correlations develop in the system.
The $N=2$ case represents the two-level system which is the paradigm of single-photon emission. In this case, there is no oscillatory dynamics but only a return to equilibrium.
The $N=3$ case was first analyzed by J. Premanand.[1] See also Refs. [2][3][4]
The general case $N$ was studied by ourselves as a mechanism to produce perfect-single photon sources.[5][6] It must be off-equilibrium so as to ensure strong-enough imbalance that trigger the oscillations.[7]
References
- ↑ Approach to Equilibrium of a Relaxing System. I. Classical 3-Level System. J. Premanand in Phys. Rev. 138:B1320 (1965).
- ↑ Reciprocal Relations in Irreversible Processes. I.. L. Onsager in Phys. Rev. 37:405 (1931).
- ↑ Rate equation solution for the temporal behavior of a three-level system. G. Zizak, J. D. Bradshaw and J. D. Winefordner in Appl. Optics 19:3631 (1980).
- ↑ Correlations in light emitted by three-level atoms. D. T. Pegg, R. Loudon and P. L. Knight in Phys. Rev. A 33:4085 (1986).
- ↑ Photon liquefaction in time. E. Zubizarreta Casalengua, E. del Valle and F. P. Laussy in APL Quant. 1:026117 (2024).
- ↑ Template:Palomomarcos25a
- ↑ General Properties of Thermal-Relaxation Rate Equations. M. W. P. Strandberg and J. R. Shane in Phys. Rev. B 7:4809 (1973).