Choi recently published a research paper on the subject of quantizing general timedependent
coupled oscillators (arXiv:2210.07551v1 [quant-ph] (2022)) using the
invariant operator approach. In the present research, we provide a direct method for
proving the correctness of such an invariant approach, together with relevant
perspectives and criticisms. The difference of our method from Choi’s one in this
context is that, while Choi managed the quantum system with the aid of the unitary
transformation technique, we do not use such an auxiliary tool in our proof of
accuracy. This demonstration may provide a definite mathematical testimony for the
usefulness of adopting invariant operator approach in a straightforward way. Our
proof is crucial in unfolding quantum information theory including optoelectromechanics
via coupled devices which operate through electro-mechanical
oscillations. We also discuss the consequences of Choi’s work and Zerimeche et al.’s
works (Mod. Phys. Lett. B 37, 2250222 (2023) and others) which share many concepts
with each other, including the relation between them.
Keywords: Coupled oscillators, Quantum dynamics, Unitary transformation,
Quantum solutions, Invariant operator
