Velocity-Dependent Threshold for Quantum Coherence in Open Systems

This work investigates the interplay between intrinsic quantum

dynamics and environmental decoherence by introducing a

characteristic velocity, v_char. This velocity marks a threshold

where the timescale associated with the system's intrinsic

energy uncertainty (T_dyn) becomes comparable to the velocity￾dependent decoherence timescale (T_coh(v)), which is governed by

system-environment coupling. We derive expressions for v_char

considering different physical scenarios, including free

particles and trapped systems, and discuss how different

decoherence mechanisms influence this threshold. For system

velocities v significantly below v_char (in cases where

decoherence accelerates at lower velocities), environmental

effects are expected to dominate over the unitary evolution

dictated by T_dyn, potentially masking quantum phenomena,

including those related to fundamental symmetries described by

Wigner's theorem. We propose experimental avenues to test this

framework using systems with tunable kinetic energy, such as

trapped ions or Bose-Einstein condensates (BECs), and discuss

the extension to trapped systems where potential energy scales

significantly influence the dynamics.