L. Gorelik, S. Kulinich,R. I. Shekhter, M. Jonson, L. Gorelik, S. Kulinich, and Yu. Galperin, Pumping of energy into a mesoscopic ring: Exactly solvable model, Low Temp. Phys. 24, (1998) [Fiz. Nizk. Temp. 24, 1181-1191, (1998)] DOI: https://doi.org/10.1063/1.593523.