  Non-zero curvature in a waveguide leads to the appearance of an attractive
quantum potential which crucially affects the dynamics in matter-wave circuits.
Using methods of supersymmetric quantum mechanics, pairs of bent waveguides are
found whose geometry-induced potentials share the same scattering properties.
As a result, reflectionless waveguides, dual to the straight waveguide, are
identified. Strictly isospectral waveguides are also found by modulating the
depth of the trapping potential. Numerical simulations are used to demonstrate
the efficiency of these approaches in tailoring and controlling
curvature-induced quantum-mechanical effects.
