Toward a global quantum network

About 90 years ago, Albert Einstein complained about the “spooky action at a distance” of quantum entanglement and questioned the completeness of quantum mechanics [1]. This year, the Nobel Prize is awarded to three pioneers that put Einstein’s curiosity under experimental tests based on Bell’s inequality [2]. The fundamentals of quantum mechanics are not of just theoretical or philosophical interest. Rather, worldwide efforts are harnessing these quantum weirdness to develop emerging technologies.