Most of the newer network cards have that ability, which is called Wake-on-LAN (WoL). What happens is that the AC power keeps the network card powered to receive special signals to turn it on.
But, with Remote Login into OS X, it is not possible, since Remote Login is simply an SSH server.
It appears this doesn't work entirely like an x86 would, because your computer cannot be woken from a power off state. With a Mac, it only works with sleep. In x86 architecture, the system could be woken from a power off state.
It appears this doesn't work entirely like an x86 would, because your computer cannot be woken from a power off state. With a Mac, it only works with sleep. In x86 architecture, the system could be woken from a power off state.