I suspect that is it. Our immortal soul may also be a component of our physical existence which resides in another dimension. Similarly, I also suspect this existence in dimensions other than our own points to a physical explanation of the trinity.
OK, so you think that the soul is our physical mind and body connecting and interacting with the heavenly dimension — sort of like transmission from this world to the other. Perhaps we leave a trace (shadow, quantum representation, or entangled property) of what we are doing and thinking in this world in the other dimension and that this trace has an independent reality that can continue to exist after our physical body is destroyed.
I would hesitate to argue that the Trinity of God is a physical property, if that is what you mean, since it would imply that God is part of the universe instead of its transcendent creator. Usually Christians believe that God is not part of the physical universe, but outside of it. He is the creator of the dimensions.
However, the idea of one person existing in two universes or dimensions could be taken as a metaphor for the trinity. Perhaps aspects of our reality is a creative reflection of God’s nature.