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Entanglement - The Holy Grail of High-Speed Design

While high-speed SERDES serial communications seems to currently be at the cutting edge of technology, maybe it will shortly become an antiquated low-speed solution--even speed-of-light fiber optics may become obsolete. This month, we’ll look at how quantum physics is transforming our world and how it could affect PCB design.

Differential signaling evolved due to the fact that high-speed, synchronous, parallel busses were getting increasingly wider--consuming more real estate--and faster until signal integrity issues forced a fundamental change in strategy. Multi-gigabit design is now the norm with up to 10 Gbps SERDES devices commonly available in FPGAs. Beyond the theoretical 12 Gbps limit, optical interconnects become the only solution. But are they?

Using quantum entanglement, devices may be able to transfer data at >10,000 times the speed of light over large distances and also possibly across time itself. Entanglement is a property in quantum physics that seemed so unbelievable and so lacking in detail that, 66 years ago, Einstein called it "spooky action at a distance.”

Einstein said, “The behaviors of materials down at the level of atoms are often strange, but entanglement borders on our concepts of sorcery.” Unfortunately, the Theory of Relativity does not describe the properties of quantum particles, and there still is a huge piece of the puzzle missing. Ideally, the laws of physics should apply equally to all matter in the universe.

If two electrons spinning in opposite directions are entangled, when one changes direction, the other immediately changes, whether the electrons are side by side, across the room or at opposite ends of the universe. Other particles, such as photons, atoms and molecules, can also become entangled, but taking advantage of the property requires more than a pair or handful.

Entanglement occurs when two particles are so intensely linked that they share the same existence. It arises naturally when two particles are created at the same point and instant in space. Entangled particles can become widely separated in space. But even so, the math implies that a measurement on one immediately influences the other, regardless of the distance between them.

Read the full column here.


Editor's Note: This column originally appeared in the November 2013 issue of The PCB Design Magazine.