Soliton phase shifts in a dissipative lattice

We measured the amplitude, width, velocity, and phase-shift characteristics of solitons in the LC lattice of Hirota and Suzuki [Proc. IEEE 61, 1483 (1974)], an inexact electrical analog of the Toda lattice. We found that dissipative effects are important in this lattice, and that amplitudes decrease, widths increase, and velocities remain constant as solitons propagate along the lattice. We found that there are distinct families of solitons, distinguished by the shape of the amplitude-width curve, and determined by the reverse bias of the input pulses that generate them. Within a family, the properties of a soliton are determined by the input amplitude and width of its generating pulse. Marked phase shifts occur when solitons of different families collide head-on, and these phase shifts are found to be independent (within experimental error) of the location of the collision on the lattice. Thus, the positional phase of solitons can be used to encode information in a simple way, and the lattice used to perform computation, of which parity checking is a simple example.