Quantum Gate

It may not be entirely obvious from the photograph (which I took at night, while hashing) but this is a wrought iron gate.

It opens on to a front garden on Maid's Causeway, Cambridge.  Why?  I don't know.  Has an important physicist lived there?  There's no Blue Plaque, so maybe it's just an enthusiast, like me!

What does it mean?  I don't know for certain, but I suspect it is a reference to something similar to the GHSZ variant of the Bell Inequality Test.  The results of this test demonstrate that there are no hidden variables in quantum mechanics.  I say "similar" because, in GHSZ instead of 0 and 1 the spins $\downarrow$ and $\uparrow$ are used, and there's a minus instead of a plus.

If you know anything more, please tell me!