Nonreciprocity and the second law of thermodynamics: An exact relation for nonlinear mediaO. Narayan1 and A. Dhar2
1 Department of Physics, University of California - Santa Cruz, CA 95064, USA
2 Raman Research Institute - Bangalore 560080, India
(Received 5 April 2004; accepted in final form 7 June 2004)
Applying monochromatic filters to the ends of a one-dimensional nonlinear medium, we find an exact identity relating the nonreciprocity -the difference in transmission from the left or right- to the power flowing with equal sources on both sides. Thus, nonreciprocity has an unanticipated link to an apparent violation of the second law of thermodynamics; this violation is only apparent because of a subtle dependence on the (arbitrarily small) filter bandwidth. At high intensities, a nonperturbative transition to a noisy state destroys the identity. Apart from the theoretical insight provided by filters, not contaminating other frequency channels has obvious advantages in communications.
05.45.-a - Nonlinear dynamics and nonlinear dynamical systems.
43.25.+y - Nonlinear acoustics.
42.65.Sf - Dynamics of nonlinear optical systems; optical instabilities, optical chaos and complexity, and optical spatio-temporal dynamics.
© EDP Sciences 2004