Self-alignment unwraps the spiraling of a chiral active Brownian polymer

Chiral active Brownian polymers in two dimensions spontaneously fold into long-lived spirals, which profoundly reshape their conformations and dynamics. Using Brownian dynamics simulations, we show that a minimal self-alignment mechanism, namely, an aligning torque that rotates the propulsion direction toward the instantaneous monomer velocity, robustly unwraps these spirals. The same mechanism drives torque-induced swelling in both chiral and achiral active chains. We quantify the structure via the radius of gyration and the end-to-end distance as functions of the alignment torque at a fixed activity and find systematic increases with torque. Distributions of the radius of gyration broaden markedly under alignment, revealing access to a wide ensemble of open conformations consistent with spiral unwrapping. Dynamical signatures corroborate this picture: the oscillatory end-to-end time correlation and the oscillations in the monomer mean-squared displacement, hallmarks of chiral rotation, are progressively suppressed as the alignment strengthens. These effects persist across intrinsic rotation frequencies, establishing self-alignment as a simple and generic control knob to release chiral polymers from spiral states and expand their conformational and dynamical repertoire.