Sure, we think of logic gates carrying electrons, but there are so many other mechanical means to do the same thing. ... You can see videos of how a D latch looks using both methods, below.

By adding a few extra logic gates, we can build this circuit, which is called a Gated Latch since the "gate" can be opened or closed. Now this circuit is starting to get a little complicated.

Kuekes was previously awarded a patent on the crossbar latch (U.S. 6,586,965) in July 2003, and the Journal of Applied Physics report, titled “The crossbar latch: Logic value storage, restoration and ...