• M LAKSHMANAN

Articles written in Indian Academy of Sciences Conference Series

• $PT$-symmetric nonlinear systems and their implication in optics

In this paper, we briefly review a few interesting dynamical aspects and applications of nonlinear $PT$-symmetric systems. Being at the boundary between dissipative and conservative systems, these $PT$-symmetric systems show many interesting characteristics and applications that cannot be seen in the usual dissipative and conservative ones. Among the variety of applications, we here focus on the applicability of $PT$-symmetric systems in unidirectional light transport. This particular application clearly evidences the usefulness of the non-reciprocal nature and symmetry broken phase of a PT-symmetric system and importantly the role of nonlinearities in optics.

• Implementation of parallel logic elements in a quasiperiodically driven Murali–Lakshmanan–Chua circuit system

We investigate the effect of deterministic input signals on a quasiperiodically driven Murali–Lakshmanan–Chua (QPDMLC) circuit, which exhibits strange nonchaotic attractors (SNAs). We show that if one uses two-square waves in an aperiodic manner as an input to a QPDMLC circuit, the response of the circuit canproduce a logical output, controlled by such forcing. We also demonstrate that one of the variables of the circuit exhibits one logic element, while the other variable shows its complementary logic operation. It is further shown that these logical behaviors persist even for an experimental noise floor. Thus we confirm that SNA is an efficient tool for computation as in the case of the quasiperiodically driven Duffing oscillator.