I'm no expert... But I don't think that it is possible, since teleporters teleport everything on them. Meaning, instead, we need to prevent the teleporter from working when more than one player stands on it.
The thing is, we need some way to detect how many players are currently on the teleporter... everything after that is more or less trivial.
The thing is, I'm not aware of any switch that can detect the amount of players. Which means we need some sort of contraption. A contraption based on player location could work, but only under the assumption that two players will never enter the teleporter at the same time... which just relocates the issue to one step prior to activating the teleporter.
There might be other contraptions I simply don't know of, that use more technical knowledge of the game, but with my knowledge I'd say no.
I'd be interested to see if there is such a contraption, though.