They can be physical, but I'm not claiming to know definitively. The lines are extremely blurry, and I'll agree that current models have at least some of the necessary components for qualia, but again lack a sensory feedback loop. In another comment [0] I quote myself as saying:

  As an independent organism, my system is a culmination of a great deal many different kinds of kins, which can usually be broken down into simple rules, such as the activation potential of a neuron in my brain being a straight-forward non-linear response to the amount of voltage it is receiving from other neurons, as well as non-kins, such as a protein "walking" across a cell, a.k.a continuously "falling" into the lowest energy state. Thus I do not gain any conscious perception from such proteins, but I do gain it from the total network effect of all my brain's neuronal structures making simple calculations based on sensory input.

which attempts to address why physically-based qualia doesn't invoke panpsychism.

[0] https://news.ycombinator.com/item?id=46109999