  The paper focuses on aspects of the measurement problem introducing quantum
states (q-states) for measured and measuring systems. The link between
non-interacting and interacting quantum systems is first look at. For two
independent partite systems logical sums A+B stand for non-interacting
q-systems; while a direct product space AxB gathers interacting states. However
this latter should support physical q-states with base states that do not
separately belong to either A nor B; the latter correspond to bridge states,
namely entangled states that can perform as links (bridges) between A+B and AxB
domains. Bridge states at laboratory space open possibilities to describe
transport in quantized amounts of energy and angular momentum. These link bases
sustain entanglements of different kinds. Interactions bring in quantized
electromagnetic (em) fields. Matter sustained q-states entangled to
em-sustained q-states open bridges to transport information between matter and
radiation.
